Exam 3: Systems of Equations

Graph the inequality on a plane. -

Solve. -Some people must eat a low-sodium diet with no more than 2000 mg of sodium per day. By eating 1 cracker, 1 pretzel, and 1 cookie, a person would ingest 149 mg of sodium. If a person ate 8 pretzels and 8 cookies, he or she Would ingest 936 mg of sodium. By eating 6 crackers and 7 pretzels, the person would take in 535 mg of sodium. Find the amount of sodium in each. Which of the following is true?

Solve the system of equations by the elimination method. -x - 3y = -24 5x - 2y = -16

Solve. -Jane wants to buy a photocopier. The salesperson has the following information on 3 models. If all 3 are used, a specific job can be done in 50 minutes. If copier A operates for 20 minutes and copier B for 50 minutes, one-half The job is finished. If copier B operates for 30 minutes and copier C for 80 minutes, three-fifths of the job is done. Which is the fastest copier, and how long does it take for this copier to finish the whole job?

Choose the ordered pair which is a solution of the inequality. -

Solve. -The sum of three numbers is -6. The first, minus the second, plus 2 times the third, is -2. The third, plus 5 times the first, plus the second, is 2. What are the numbers?

Choose the ordered pair which is a solution of the inequality. -

Classify the system as consistent or inconsistent, and dependent or independent. -5x + 4y = 3 10x + 8y = 6

Solve graphically. -

Solve the problem. -A merchant has coffee worth $20 a pound that she wishes to mix with 80 pounds of coffee worth $80 a pound to get a mixture that can be sold for $60 a pound. How many pounds of the $20 coffee should be used?

Classify the system as consistent or inconsistent, and dependent or independent. -x - 4 = y y + 5 = x

Solve. -A cabin cruiser travels 20 miles in the same time that a power boat travels 40 miles. The cruiser travels 5 mph slower than the power boat. Find the speed of each boat.

Solve. -A cruise boat travels 96 miles downstream in 3 hours and returns to its starting point upstream in 6 hours. Find the speed of the stream.

Classify the system as consistent or inconsistent, and dependent or independent. -x + 4y = 16 5x - 2y = 14

Solve using the substitution method. -y = 2x + 4 3x + y = 29

Solve. -x + y + z = -5 x - y + 3z = -11 5x + y + z = -21

Solve. -A company makes 3 types of cable. Cable A requires 3 black, 3 white, and 2 red wires. B requires 1 black, 2 white, and 1 red. C requires 2 black, 1 white, and 2 red. They used 100 black, 110 white and 80 red wires. How Many of each cable were made?

Match the inequality with a graph. -

Graph the inequality on a plane. -

Solve the problem. -Ellen wishes to mix candy worth $1.08 per pound with candy worth $3.05 per pound to form 24 pounds of a mixture worth $2.64 per pound. How many pounds of the more expensive candy should she use?