Deck 11: Systems of Equations

Question 1

Solve the system of equations by graphing the equations on the same set of axes.

- $$\left\{ \begin{aligned}x + \frac { 1 } { 3 } y & = 4 \\x & = 2\end{aligned} \right.$$

A)(2, -6)
B)(2, 6)
C)(-2, 6)
D)no solution

Answer 1

(2, 6)

Question 2

Decide whether or not the ordered pair satisfies the system of linear equations.

-(3, -1); $\left\{ \begin{array} { l } x + y = - 4 \\x - y = - 2\end{array} \right.$

Answer 2

False

Question 3

Solve the system of equations by graphing the equations on the same set of axes.

- $$\left\{ \begin{array} { l } 3 x + y = 7 \\2 x + y = 4\end{array} \right.$$

A)(-2, 3)
B)(3, -2)
C)(-3, 2)
D)no solution

Answer 3

(3, -2)

Question 4

Solve the system of equations by graphing the equations on the same set of axes.

- $$\left\{ \begin{array} { c } x - 2 y = 1 \\3 x + 2 y = - 13\end{array} \right.$$

A)(-2, -3)
B)(-3, -2)
C)(-3, 2)
D)no solution

Question 5

Decide whether or not the ordered pair satisfies the system of linear equations.

-(-6, 5); $\left\{ \begin{array} { l } x + y = - 1 \\x - y = - 11\end{array} \right.$

Question 6

Decide whether or not the ordered pair satisfies the system of linear equations.

-(2, -6); $\left\{ \begin{array} { l } 4 x + y = 2 \\2 x + 4 y = - 20\end{array} \right.$

Question 7

Decide whether or not the ordered pair satisfies the system of linear equations.

-(-4, -7); $\left\{ \begin{array} { l } 2 x = - 15 - y \\x - 3 y = 17\end{array} \right.$

Question 8

Solve the system of equations by graphing the equations on the same set of axes.

- $$\left\{ \begin{array} { l } x = - 3 \\y = - 3\end{array} \right.$$

A)(-3, -3)
B)(-3, 3)
C)(3, 3)
D)(3, -3)

Question 9

Decide whether or not the ordered pair satisfies the system of linear equations.

-(-2, -6); $\left\{ \begin{array} { l } 3 x + y = 0 \\4 x + 3 y = 10\end{array} \right.$

Question 10

Solve the system of equations by graphing the equations on the same set of axes.

- $$\left\{ \begin{array} { l } y = - 5 x \\2 x - y = - 7\end{array} \right.$$

A)(0, 7)
B)(3, -7)
C)(-1, 5)
D)(1, -5)

Question 11

Solve the system of equations by graphing the equations on the same set of axes.

- $$\left\{ \begin{array} { r } 2 x - y = 6 \\y = 2\end{array} \right.$$

A)(-4, -2)
B)(4, 2)
C)(2, 4)
D)no solution

Question 12

Decide whether or not the ordered pair satisfies the system of linear equations.

- $\begin{array} { l } \left\{ \frac { 1 } { 3 } , \frac { 1 } { 2 } \right) \\\left\{ \begin{array} { l } 2 x = 6 - y \\x - 10 y = - 8\end{array} \right.\end{array}$

Question 13

The double line graph below shows the number of Acme Superstores vs. the number of General Superstores.
In what year was the number of Acme stores approximately equal to the number of General stores?

A)2002
B)2000
C)1999
D)1998

Question 14

The double line graph below shows the number of Acme Superstores vs. the number of General Superstores.
In what years was the number of General stores greater than the number of Acme stores?

A)2000 through 2002
B)1192 through 1998
C)1999 through 2002
D)1992 through 1999

Question 15

Solve the system of equations by graphing the equations on the same set of axes.

- $$\left\{ \begin{array} { l } y = x + 4 \\y = 3 x + 6\end{array} \right.$$

A)(-1, 3)
B)(1, -3)
C)(3, -1)
D)no solution

Question 16

Decide whether or not the ordered pair satisfies the system of linear equations.

-(3, -1); $\left\{ \begin{array} { l } 3 x = 8 - y \\2 x = 3 - 3 y\end{array} \right.$

Question 17

Solve the system of equations by graphing the equations on the same set of axes.

- $$\left\{ \begin{array} { l } y = x - 1 \\y = - 2 x + 8\end{array} \right.$$

A)(3, -2)
B)(3, 2)
C)(-2, 3)
D)no solution

Question 18

Decide whether or not the ordered pair satisfies the system of linear equations.

-(4, -3); $\left\{ \begin{array} { l } 2 x = - 11 - y \\3 x = - 18 - 2 y\end{array} \right.$

Question 19

Decide whether or not the ordered pair satisfies the system of linear equations.

-(-9, -5); $\left\{ \begin{array} { l } 2 x = - 22 - y \\x + 4 y = - 29\end{array} \right.$

Question 20

Solve the system of equations by graphing the equations on the same set of axes.

- $$\left\{ \begin{array} { l } x + y = 1 \\x - y = 5\end{array} \right.$$

A)(3, 2)
B)(-2, 3)
C)(3, -2)
D)no solution

Question 21

Solve the system of equations by the substitution method.

- $\left\{ \begin{aligned}- 3 x - 5 y & = - 112 \\x & = 3 y\end{aligned} \right.$

A)(8, 24)
B)(24, 8)
C)infinite number of solutions
D)no solution

Question 22

Without graphing, decide:
(a)Are the graphs of the equations are identical lines, parallel lines, or lines intersecting at a single point?
(b)How many solutions does the system have?

- $\left\{ \begin{array} { r } \frac { 1 } { 4 } x - y = 1 \\x = 4\end{array} \right.$

A)parallel lines; no solution
B)lines intersecting at a single point; one solution
C)identical lines; infinite number of solutions

Question 23

Without graphing, decide:
(a)Are the graphs of the equations are identical lines, parallel lines, or lines intersecting at a single point?
(b)How many solutions does the system have?

- $\left\{ \begin{array} { l } 2 x + y = 3 \\2 x + y = 1\end{array} \right.$

A)parallel lines; no solution
B)lines intersecting at a single point; one solution
C)identical lines; infinite number of solutions

Question 24

Solve the system of equations by the substitution method.

- $\left\{ \begin{array} { l } \frac { 1 } { 7 } x - 2 y = 1 \\x - 14 y = 7\end{array} \right.$

A)(1, -7)
B)(7, -1)
C)infinite number of solutions
D)no solution

Question 25

Solve the system of equations by the substitution method.

- $\left\{ \begin{array} { l } x - 7 y = 1 \\- 3 x - 8 y = - 32\end{array} \right.$

A)(-8, 2)
B)(8, 1)
C)(7, 2)
D)no solution

Question 26

Without graphing, decide:
(a)Are the graphs of the equations are identical lines, parallel lines, or lines intersecting at a single point?
(b)How many solutions does the system have?

- $\left\{ \begin{aligned}x + 5 y & = 20 \\y & = - \frac { 1 } { 5 } x + 4\end{aligned} \right.$

A)identical lines; infinite number of solutions
B)parallel lines; no solution
C)lines intersecting at a single point; one solution

Question 27

Solve the system of equations by the substitution method.

- $\left\{ \begin{array} { l } - 3 x + y = 28 \\- 4 x + 7 y = 77\end{array} \right.$

A)(-7, 7)
B)(7, -7)
C)(-6, 6)
D)no solution

Question 28

Without graphing, decide:
(a)Are the graphs of the equations are identical lines, parallel lines, or lines intersecting at a single point?
(b)How many solutions does the system have?

- $\left\{ \begin{aligned}x & = - y \\y + x & = 5\end{aligned} \right.$

A)parallel lines; no solution
B)identical lines; infinite number of solutions
C)lines intersecting at a single point; one solution

Question 29

Without graphing, decide:
(a)Are the graphs of the equations are identical lines, parallel lines, or lines intersecting at a single point?
(b)How many solutions does the system have?

- $\left\{ \begin{aligned}3 x - y & = 1 \\x + 4 y & = 22\end{aligned} \right.$

A)lines intersecting at a single point; one solution
B)parallel lines; no solution
C)identical lines; infinite number of solutions

Question 30

Without graphing, decide:
(a)Are the graphs of the equations are identical lines, parallel lines, or lines intersecting at a single point?
(b)How many solutions does the system have?

- $\left\{ \begin{array} { l } x + y = 6 \\x + y = 3\end{array} \right.$

A)lines intersecting at a single point; one solution
B)parallel lines; no solution
C)identical lines; infinite number of solutions

Question 31

Solve the system of equations by the substitution method.

- $\left\{ \begin{aligned}y & = 4 x + 2 \\3 y - 9 x & = 15\end{aligned} \right.$

A)(14, 3)
B)(3, 14)
C)infinite number of solutions
D)no solution

Question 32

Solve the system of equations by the substitution method.

- $\left\{ \begin{array} { l } - 6 x - 24 y = 6 \\2 x + 8 y = 0\end{array} \right.$

A)(0, 6)
B)(6, 0)
C)infinite number of solutions
D)no solution

Question 33

Solve the system of equations by the substitution method.

- $\left\{ \begin{array} { r } x + y = - 10 \\y = - 3 x\end{array} \right.$

A)(5, -15)
B)(-15, 5)
C)infinite number of solutions
D)no solution

Question 34

Solve the system of equations by the substitution method.

- $\left\{ \begin{array} { l } 4 y = x + 40 \\2 x + 8 y = 0\end{array} \right.$

A)(-20, 5)
B)(5, -20)
C)infinite number of solutions
D)no solution

Question 35

Without graphing, decide:
(a)Are the graphs of the equations are identical lines, parallel lines, or lines intersecting at a single point?
(b)How many solutions does the system have?

- $\left\{ \begin{array} { l } 2 x + y = - 7 \\4 x + 5 y = - 5\end{array} \right.$

A)identical lines; infinite number of solutions
B)parallel lines; no solution
C)lines intersecting at a single point; one solution

Question 36

Solve the system of equations by the substitution method.

- $\left\{ \begin{array} { l } - 9 y = x - 79 \\2 x + 8 y = 68\end{array} \right.$

A)(-2, 9)
B)(2, 10)
C)(-3, 10)
D)no solution

Question 37

Solve the system of equations by the substitution method.

- $\left\{ \begin{array} { l } y = 5 x - 7 \\y = 8 x - 6\end{array} \right.$

A) $\left( - \frac { 1 } { 3 } , - \frac { 26 } { 3 } \right)$
B) $\left( - \frac { 26 } { 3 } , - \frac { 1 } { 3 } \right)$
C)infinite number of solutions
D)no solution

Question 38

Solve the system of equations by the substitution method.

- $\left\{ \begin{array} { l } - 6 y + 7 y = - 1 x + 2 ( x - 3 ) + 1 x + 3 \\5 ( x + y ) - x + y = - 2\end{array} \right.$

A)(-1, 1)
B)(1, -1)
C)infinite number of solutions
D)no solution

Question 39

Solve the system of equations by the substitution method.

- $\left\{ \begin{array} { l } 2 x + y = 7 \\6 x + 3 y = 21\end{array} \right.$

A)(5, -3)
B)(0, 7)
C)infinite number of solutions
D)no solution

Question 40

Without graphing, decide:
(a)Are the graphs of the equations are identical lines, parallel lines, or lines intersecting at a single point?
(b)How many solutions does the system have?

- $\left\{ \begin{aligned}y - 2 x & = 3 \\6 y & = 12 x + 18\end{aligned} \right.$

A)identical lines; infinite number of solutions
B)parallel lines; no solution
C)lines intersecting at a single point; one solution

Question 41

Without solving, choose the correct solution by deciding which choice satisfies the given conditions.
Rozlyn has two containers of water for a camping trip. One container holds 2 times as much as the other. The total amount of water is 18 gallons. How much water is in each container?

A)5 gallons; 13 gallons
B)6.5 gallons; 11.5 gallons
C)6 gallons; 12 gallons
D)18 gallons; 6 gallons

Question 42

Solve the system of equations by the addition method.

- $\left\{ \begin{array} { l } 4 x - 4 y = 10 \\20 x - 20 y = 40\end{array} \right.$

A)(10, 40)
B) $\left( \frac { 25 } { 12 } , - \frac { 25 } { 12 } \right)$
C)(5, 4)
D)no solution

Question 43

Solve the system of equations by the addition method.

- $\left\{ \begin{array} { l } 3 x - 5 y = 3 \\2 x - 3 y = 3\end{array} \right.$

A)(6, 3)
B)(3, 6)
C)infinite number of solutions
D)no solution

Question 44

Solve the system of equations by the substitution method.

- $\left\{ \begin{array} { l } y = 1.2 x - 2.3 \\y = 0.8 x - 2.02\end{array} \right.$

A)(0.7, -1.46)
B)(-0.7, -1.46)
C)infinite number of solutions
D)no solution

Question 45

Solve the system of equations by the addition method.

- $\left\{ \begin{array} { r r } 7 x + 2 y = & 9 \\- 2 x - 2 y = & - 24\end{array} \right.$

A)(2, -15)
B)(-3, 15)
C)(7, -15)
D)infinite number of solutions

Question 46

Solve the system of equations by the addition method.

- $\left\{ \begin{array} { l } 2 x + 3 y = 14 \\3 x + 5 y = 19.2\end{array} \right.$

A)(-3.6, 12.4)
B)(12.4, -3.6)
C)infinite number of solutions
D)no solution

Question 47

Solve the system of equations by the addition method.

- $\left\{ \begin{array} { l } \frac { x } { 5 } + \frac { y } { 5 } = 3 \\\frac { x } { 2 } - \frac { y } { 2 } = \frac { 3 } { 2 }\end{array} \right.$

A)(9, 6)
B)(6, 9)
C)infinite number of solutions
D)no solution

Question 48

Solve the system of equations by the addition method.

- $\left\{ \begin{array} { r } x - 5 y = - 26 \\6 x - 6 y = - 60\end{array} \right.$

A)(-6, 4)
B)(6, 5)
C)(-7, 5)
D)no solution

Question 49

Without solving, choose the correct solution by deciding which choice satisfies the given conditions.
At the local convenience store, 3 bags of chips and 4 containers of dip cost $25. However, 4 bags of chips and 7 containers of dip cost $40. What is the cost of one bag of chips and one container of dip?

A)chips = $3.50; dip = $3.50
B)chips = $4; dip = $3
C)chips = $5; dip = $5
D)chips = $3; dip = $4

Question 50

Solve the system of equations by the addition method.

- $\left\{ \begin{array} { l } x + y = - 12 \\x - y = - 12\end{array} \right.$

A)(0, 12)
B)(-12, 0)
C)(12, 0)
D)(0, -12)

Question 51

Solve the system of equations by the addition method.

- $\left\{ \begin{array} { l } 3 x - 5 y = - 10 \\5 x - 4 y = - 21\end{array} \right.$

A)(-5, -1)
B)(5, -1)
C)(-5, 1)
D)(5, 1)

Question 52

Solve the system of equations by the addition method.

- $\left\{ \begin{array} { l } - 6 x - 6 y = - 6 \\12 x + 12 y = 12\end{array} \right.$

A)(-6, -6)
B)(0, 0)
C)infinite number of solutions
D)no solution

Question 53

Solve the system of equations by the addition method.

- $\left\{ \begin{array} { r } x + 8 y = - 39 \\2 x + 8 y = - 46\end{array} \right.$

A)(4, -7)
B)(-7, -4)
C)infinite number of solutions
D)no solution

Question 54

Solve the system of equations by the addition method.

- $\left\{ \begin{array} { l } 2 x + \frac { 2 } { 3 } y = - 16 \\2 x - \frac { 2 } { 3 } y = - 8\end{array} \right.$

A)(-6, -6)
B)(-5, -7)
C)(6, -7)
D)no solution

Question 55

Solve the system of equations by the addition method.

- $\left\{ \begin{array} { l } x + y = 11 \\x - y = - 7\end{array} \right.$

A)(1, 10)
B)(-2, 10)
C)(2, 9)
D)no solution

Question 56

Solve the system of equations by the addition method.

- $\left\{ \begin{array} { l } \frac { x } { 5 } + \frac { y } { 10 } = 1 \\\frac { x } { 3 } - \frac { y } { 6 } = 0\end{array} \right.$

A) $\left( 5 , \frac { 5 } { 2 } \right)$
B) $\left( \frac { 5 } { 2 } , 5 \right)$
C)infinite number of solutions
D)no solution

Question 57

Solve the system of equations by the addition method.

- $\left\{ \begin{array} { l } x + y = - 6 \\x + y = - 8\end{array} \right.$

A)(0, 0)
B)(0, -14)
C)(-6, -8)
D)no solution

Question 58

Without solving, choose the correct solution by deciding which choice satisfies the given conditions.
Zacharias has a total of 61 coins, all of which are either dimes or nickels. The total value of the coins is $5.45. Find the number of each type of coin.

A)48 nickels; 13 dimes
B)13 nickels; 48 dimes
C)18 nickels; 43 dimes
D)15 nickels; 46 dimes

Question 59

Solve the system of equations by the addition method.

- $\left\{ \begin{array} { l } 5 x + y = - 18 \\6 x - y = 7\end{array} \right.$

A)(-1, -13)
B)(-13, -1)
C)infinite number of solutions
D)no solution

Question 60

Solve the system of equations by the addition method.

- $\left\{ \begin{array} { l } 3 x - 5 y = - 7 \\3 x - 5 y = 8\end{array} \right.$

A)(-7, 8)
B) $\left( - \frac { 7 } { 5 } , \frac { 8 } { 3 } \right)$
C)(3, 5)
D)no solution

Question 61

Solve the problem.
On a buying trip in Los Angeles, Rosaria Perez ordered 120 pieces of jewelry: a number of bracelets at $5 each and a number of necklaces at $15 each. She wrote a check for $1400 to pay for the order. How many bracelets
And how many necklaces did Rosaria purchase?

A)40 bracelets and 80 necklaces
B)35 bracelets and 85 necklaces
C)45 bracelets and 75 necklaces
D)50 bracelets and 70 necklaces

Question 62

Solve the problem.

-Jimmy is a partner in an Internet-based coffee supplier. The company offers gourmet coffee beans for $14 per pound and regular coffee beans for $5 per pound. Jimmy is creating a medium-price product that will sell for $7 per pound. The first thing to go into the mixing bin was 10 pounds of the gourmet beans. How many pounds Of the less expensive regular beans should be added?

A)34 pounds
B)35 pounds
C)37 pounds
D)36 pounds

Question 63

Solve the problem.

-The sum of two numbers is 6. Five times the first number equals 2 times the second number. Find the two numbers.

A)6 and 10
B) $- \frac { 12 } { 7 } \text { and } - \frac { 30 } { 7 }$
C)12 and 30
D) $\frac { 12 } { 7 } \text { and } \frac { 30 } { 7 }$

Question 64

Solve the problem.
Khang and Hector live 32.4 miles apart in southeastern Missouri. They decide to bicycle towards each other and meet somewhere in between. Hector's rate of speed is 80% of Khang's. They start out at the same time and meet
3 hours later. Find Hector's rate of speed.

A)6 mph
B)18 mph
C)32.4 mph
D)4.8 mph

Question 65

Solve the problem.

-Natasha rides her bike (at a constant speed)for 3 hours, helped by a wind of 3 miles per hour. Pedaling at the same rate, the trip back against the wind takes 9 hours. Find find the total round trip distance she traveled.

A)54 miles
B) $\frac { 27 } { 2 }$ miles
C)27 miles
D)12 miles

Question 66

Solve the problem.
Dmitri needs 6 liters of a 46% solution of sulfuric acid for a research project in molecular biology. He has two supplies of sulfuric acid solution: one is an unlimited supply of the 54% solution and the other an unlimited
Supply of the 30% solution. How many liters of each solution should Dmitri use?

A)54% solution: 4.5 liters; 30% solution: 1.5 liters
B)54% solution: 4 liters; 30% solution: 2 liters
C)54% solution: 2 liters; 30% solution: 4 liters
D)54% solution: 3.5 liters; 30% solution: 2.5 liters

Question 67

Solve the problem.
A barge takes 4 hours to move (at a constant rate)downstream for 32 miles, helped by a current of 2 miles per hour. If the barge's engines are set at the same pace, find the time of its return trip against the current.

A)6 hours
B)64 hours
C)4 hours
D)8 hours

Question 68

Solve the problem.
One number is four more than a second number. Two times the first number is 4 more than four times the second number.

A)6 and 2
B)7 and 3
C)- 6 and - 10
D)5 and 1

Question 69

Solve the problem.
Devon purchased tickets to an air show for 5 adults and 2 children. The total cost was $167. The cost of a child's ticket was $4 less than the cost of an adult's ticket. Find the price of an adult's ticket and a child's ticket.

A)adult's ticket: $25; child's ticket: $21
B)adult's ticket: $24; child's ticket: $20
C)adult's ticket: $27; child's ticket: $23
D)adult's ticket: $26; child's ticket: $22

Question 70

Solve the problem.

-Jarod is having a problem with rabbits getting into his vegetable garden, so he decides to fence it in. The length of the garden is 12 feet more than 6 times the width. He needs 136 feet of fencing to do the job. Find the length
And width of the garden.

A)length: 66 feet; width: 9 feet
B)length: 54 feet; width: 7 feet
C)length:length: $118 \frac { 2 } { 7 }$ f feet; width: $17 \frac { 5 } { 7 }$ fee feet
D)length: 60 feet; width: 8 feet

Question 71

Solve the problem.
Chandra has 3 liters of a 24% solution of sodium hydroxide in a container. What is the amount and concentration of sodium hydroxide solution she must add to this in order to end up with 8 liters of 54%
Solution?

A)5 liters of 75% solution
B)5 liters of 70% solution
C)5 liters of 73% solution
D)5 liters of 72% solution

Question 72

Solve the problem.

-Kelly is a partner in an Internet-based seed and garden supply business. The company offers a blend of exotic wildflower seeds for $105 per pound and a blend of common wildflower seeds for $15 per pound. Kelly is Creating a medium-price product by mixing together 32 pounds of the more expensive blend with 7 pounds of The less expensive blend. What will be the price per pound for the new blend? (Round to the nearest cent, if Necessary.)

A)$28.88 per pound
B)$10.13 per pound
C)$88.85 per pound
D)$31.15 per pound

Question 73

Write a system of equations to describe the situation. Do not solve the system.

-Leroy has $14 less in his pocket than Zoe has. If Zoe had $5 more, she would have 2 times as much money as Leroy.

A) $\left\{ \begin{array} { l } x = y - 14 \\y = 5 = 2 x\end{array} \right.$
B) $\left\{ \begin{array} { l } y = x - 14 \\y + 5 = 2 x\end{array} \right.$
C) $\left\{ \begin{array} { l } x = y - 14 \\y + 5 = 2 x\end{array} \right.$
D) $\left\{ \begin{array} { l } x = y - 14 \\y + 5 = x + 2\end{array} \right.$

Question 74

Solve the problem.
The three angles in a triangle always add up to 180°. If one angle in a triangle is 114° and the second is 5 times the third, what are the three angles?

A)114°, 54°, 12°
B)114°, 53°, 13°
C)114°, 56°, 10°
D)114°, 55°, 11°

Question 75

Solve the problem.
Jamil always throws loose change into a pencil holder on his desk and takes it out every two weeks. This time it is all nickels and dimes. There are 3 times as many dimes as nickels, and the value of the dimes is $1.75 more
Than the value of the nickels. How many nickels and dimes does Jamil have?

A)7 nickels and 21 dimes
B)6 nickels and 18 dimes
C)21 nickels and 7 dimes
D)8 nickels and 24 dimes

Question 76

Write a system of equations to describe the situation. Do not solve the system.

-An order of 4 orders of fries, 3 hamburgers, and 5 drinks costs $15. An order of 4 orders of fries, 3 hamburgers, and 2 drinks costs $12. All drinks are $1.

A) $\left\{ \begin{array} { l } 4 x + 3 y + 5 = 10 \\4 x + 3 y + 2 = 10\end{array} \right.$
B) $\left\{ \begin{array} { l } 4 x + 3 y + 5 = 15 \\4 x + 3 y + 2 = 12\end{array} \right.$
C) $\left\{ \begin{array} { l } ( 4 x ) ( 3 y ) + 5 = 15 \\( 4 x ) ( 3 y ) + 2 = 12\end{array} \right.$
D) $\left\{ \begin{array} { l } 4 x + 3 y + 1 = 15 \\4 x + 3 y + 1 = 12\end{array} \right.$

Question 77

Solve the problem.
Julie and Eric row their boat (at a constant speed)35 miles downstream for 5 hours, helped by the current. Rowing at the same rate, the trip back against the current takes 7 hours. Find the rate of the current.

A)2 mph
B)0.5 mph
C)1 mph
D)6 mph

Question 78

Write a system of equations to describe the situation. Do not solve the system.

-One number is 5 more than another number. If you add 9 to 2 times the first number, the result is 3 times the second number.

A) $\left\{ \begin{array} { l } x - y = 5 \\2 x - 3 y = - 9\end{array} \right.$
B) $\left\{ \begin{array} { l } x - y = 5 \\2 x - 3 y = 9\end{array} \right.$
C) $\left\{ \begin{array} { l } x - y = 5 \\- 2 x + 3 y = - 9\end{array} \right.$
D) $\left\{ \begin{array} { l } x + y = 5 \\2 x - 3 y = - 9\end{array} \right.$

Question 79

Solve the problem.
Two numbers total 10, and their difference is 16. Find the two numbers.

A)6 and 4
B)10 and 2
C)13 and - 3
D)5 and - 11

Question 80

Solve the problem.
Doreen and Irena plan to leave their houses at the same time, roller blade towards each other, and meet for lunch after 2 hours on the road. Doreen can maintain a speed of 6.6 miles per hour, which is 60% of Irena's
Speed. If they meet exactly as planned, what is the distance between their houses?

A)13.2 miles
B)21.12 miles
C)22 miles
D)35.2 miles