5.4 Direct, Joint and Inverse Variation

 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

Is the given table a direct variation? If so, what is the constant of variation?

• Yes; 1/3
• Yes; 3
• Yes; 5
• No

Which of the given graphs is a direct variation?

• A
• B
• C
• D

Tags

CCSS.8.EE.B.5

Is the given table a direct or inverse variation? What is the constant of variation?

• Direct, 12
• Inverse, 12
• Direct, 1/12
• Inverse, 1/12

The number of hours to paint a house varies inversely with the number of painters working. A 2400-square foot house can be painted in 27 hours by 6 painters. How many painters would need to work in order to paint the house in 18 hours?

• 8 painters
• 10 painters
• 9 painters
• 11 painters

Trina's paycheck earnings varies directly as the number of hours she works. If she works 19 hours and earns $187.15, what should she earn if she worked 40 hours? 

• $394
• $443.25
• $472.80
• $512.20

Tags

CCSS.HSF-LE.A.1B

State what type of variation the equation represents.

• Direct

• Inverse

• Joint

• None

State what type of variation the equation represents.

• Direct

• Inverse

• Joint

• None

Suppose y varies directly as x, and y=39 when x=3.  Find the value of y when x=2.

• 26
• 3
• 58.5
• 2

Suppose y varies jointly as x & z. 
If y = -180 when z = 15
and x = -3,
then find y when x = 7 and z = -5.

• -140
• 140
• -4
• 4