Exam 7: Rational Expressions and Equations

Solve. -The weight of a liquid varies directly as its volume V. If the weight of the liquid in a cubical container 4 cm on a side is 192 g, find the weight of the liquid in a cubical container 3 cm on a side.

Write the word or phrase that best completes each statement or answers the question. -Explain why, when one number is a factor of another, the least common denominator of the numbers is the larger number.

Solve. -It takes 9 hours for 8 people to paint a house. How long will it take 2 people to do the job?

Find an equation of variation in which y varies inversely as x and the following is true. -y = 0.6, when x = 0.2

Solve. -The intensity I of light varies inversely as the square of the distance D from the source. If the intensity of illumination on a screen 5 ft from a light is 2 foot candles, find the intensity on a screen 20 ft from the light. Express the answer as a fraction.

Subtract. Simplify, if possible. -

Multiply. Do not simplify. -

Multiply and, if possible, simplify. -

Multiply. Do not simplify. -

Divide and simplify. -

Solve the equation. -

Add, first finding the LCD. Simplify, if possible. -1

Solve the problem. -Dr. Wong can see 9 patients in 2 hours. At this rate, how long would it take her to see 90 patients?

Multiply and, if possible, simplify. -

Simplify. -

Find the LCM. -

Multiply and, if possible, simplify. -

Solve. -The force needed to keep a car from skidding on a curve varies jointly as the weight of the car and the square of the car's speed, and inversely as the radius of the curve. If a force of 3600 pounds is needed to keep an 1800 pound car traveling at 20 mph from skidding on a curve of radius 600 feet, what force would be required To keep the same car from skidding on a curve of radius 550 feet at 30 mph? Round your answer to the nearest Pound of force?

Divide and simplify. -

Solve the problem. -A man rode a bicycle for 12 miles and then hiked an additional 8 miles. The total time for the trip was 5 hours. If his rate when he was riding a bicycle was 10 miles per hour faster than his rate walking, what was each rate?