Direct Variation

Which of the given graphs is a direct variation?

• A

• B

• C

• D

What does "k" stand for in the direct variation equation?

• constant of equality

• constant of proportionality

• constant of non-proportionality

Which of the following is the equation format for direct variation?

• y = mx + b

• y = kx

The size of a box varies directly as its mass. A 20 cubic centimeter box has a mass of 40 kg. What is the size of the box if the mass is 100 kg.

• 8 cubic centimeters

• 50 cubic centimeters

• 80 cubic centimeters

• 200 cubic centimeters

On a scale, yards vary directly as feet. If 3 feet represent 30 yards, how many yards represent 5 feet.

• 0.5 yards

• 18 yards

• 32 yards

• 50 yards

Suppose y varies directly as x. If y = -7 when x = -14, find x when y = 10.

• -5

• 3

• 9.8

• 20

Is this a direct variation?

• yes

• no

Y varies directly with x, and y is 84 when x is 16. Which equation represents this situation?

• y=1344x

• y=100x

• y=5.25x

• y=4/21x

What type of relationship is a direct variation.

• proportional

• non-proportional

What is the equation to find "k", the constant of proportionality?

• y = kx

• y = mx + b