Direct, Inverse, Joint & Combined Variation

Which of the following represents direct variation?

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

Tags

CCSS.HSF.BF.A.1

Which of the following represents inverse variation?

• y = kx

• y = k/x

• y = x/k

• y = mx + b

Y varies inversely with x, and y is 0.5 when x is 4. Which equation represents this situation?

• y=2x

• y=2/x

• y=4x

• y=x/2

y varies directly as x, if y=4 when x=3, find x when y=-12

• -16
• 16
• -9
• 9

Tags

CCSS.8.EE.C.7

CCSS.8.F.A.3

CCSS.8.F.B.4

y varies inversely as x, if y = -3 when x = -6, find y when x = 14.

• 11
• -11
• 9/7
• 7/9

Tags

CCSS.HSA.CED.A.1

CCSS.HSA.CED.A.2

CCSS.HSA.REI.A.1

Which equation represents an inverse variation?

• xy = 40

• y = x/40

• y/x = 40
• x = y/40

Which equation below represents a direct variation?

• y = -2x
• y = -3x -5
• y = -1
• x + 3y = 15

Tags

CCSS.HSF.BF.A.1

What is the constant (k) in this inverse variation?
y = 400/x

• x
• y
• 400
• Not enough information given

Tags

CCSS.HSF-LE.A.1B

The equation 
xy =  25  represents:

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

Tags

CCSS.HSA.CED.A.2

CCSS.HSA.REI.D.10

If y varies jointly with the product of x and z, and y = 105 when x = 5 and z = 7, find y when x = 9 and z = 10.

• 270

• 180

• 360

• 255