Direct and Inverse Variation

• direct variation
• inverse variation
• neither direct nor inverse variation

Tags

CCSS.8.EE.B.5

CCSS.8.EE.B.6

CCSS.8.F.A.1

CCSS.8.F.A.3

CCSS.8.F.B.4

CCSS.8.F.B.5

CCSS.8.SP.A.2

• direct variation
• inverse variation
• neither direct nor inverse variation

Tags

CCSS.8.EE.B.5

The equation  xy =  25  represents: (a)  

• direct variation
• inverse variation
• joint variation
• none of these

Suppose y varies inversely with x.
If y = 150 when x = 2, find y when x = 25.

Mathematical Equivalence

ON

Which of the following represents direct variation?

• y = kx
• y = k/x
• y = x/k
• y = mx + b

Tags

CCSS.8.EE.B.5

CCSS.8.EE.B.6

CCSS.8.F.B.4

CCSS.8.SP.A.2

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

• Yes; 1/3
• Yes; 3
• Yes; 5
• No

Tags

CCSS.8.EE.B.5

CCSS.8.F.A.2

CCSS.8.F.B.4

Which of the given graphs is a direct variation? (a)  

• A
• B
• C
• D

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

Tags

CCSS.8.EE.B.5

CCSS.8.F.B.4

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?  (a)  

• $394
• $443.25
• $472.80
• $512.20

Write an equation for this relationship. (a)  

• y=4x
• y=1/8x
• y=1/4x
• y=8x