Direct Variation

In a direct variation, y=39 when x=3.  Find the value of y when x=2.

• 26
• 3
• 58.5
• 2

Is this a direct variation?
y=2x

• yes
• no

What does the Direct Variation Equation look like?

• y= kx
• y = mx + b
• y = b
• y = x

 y varies directly with x, and y is 16 when x is 32. Which equation represents this situation?

• y=32x
• y=16x
• y=2x
• y=(1/2)x

What ordered pair does a direct variation always go through when graphed?

• (0, 0)
• (1, 0)
• (0, 1)
• (1, 1)

What is another name for k?

• y- intercept
• x 
• slope
• x- intercept

Tags

CCSS.8.EE.B.6

CCSS.8.F.A.3

 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

If y = 15 when x = 12 find y when x = 32.

• y = (5/4)x; 40
• y= (4/5)x; -40
• y= 4x; 5
• y= 5x; -5

Tags

CCSS.8.F.B.4

CCSS.HSF.LE.A.2

If y =4 when x = -4, find y when x =7.

• y= x, 7
• y= -x; 7
• y = -x; -7
• y= x; -7

Tags

CCSS.8.F.B.4

CCSS.HSF.LE.A.2

If y vaires directly with x and y= 12 when x= 15. What is the value of x when y= 16?

• 12.8
• 20
• 11.25
• 19