Direct Variation

Is this direct variation?

• yes
• no

Answer explanation

To be direct variation, a graph must be a LINE and pass through (0,0).

Tags

CCSS.8.EE.B.5

CCSS.8.EE.B.6

CCSS.8.F.A.3

CCSS.8.F.B.4

CCSS.8.SP.A.3

Is this direct variation?

• yes
• no

Answer explanation

To be direct variation, a graph must be a LINE and pass through (0,0).

Tags

CCSS.8.EE.B.5

CCSS.8.EE.B.6

CCSS.8.F.A.3

CCSS.8.F.B.4

CCSS.8.SP.A.2

CCSS.8.SP.A.3

Which of the given graphs is a direct variation?

• A
• B
• C
• D

Answer explanation

To be direct variation, a graph must be a LINE and pass through (0,0).

Tags

CCSS.8.EE.B.5

Which equation(s) represent direct variation?

• y = 3x + 2

• 2y = 10x + 6

• 8x - 3y = 0

• -4y = 2x

Answer explanation

Make sure to solve for y and then check if your equation looks like y = mx.

Direct Variation must be in the form y = mx where the y-intercept is 0.

Tags

CCSS.8.EE.B.6

CCSS.8.F.A.3

The value of y varies directly with x.  Which function represents the relationship between x and y if y = 14 when x = 6. 

• y=20x
• y=84x
• y=7/3x
• y=3/7x

Answer explanation

Because direct variation is PROPORTIONAL, the slope (constant of variation) can be found by y/x.

y = mx is the correct equation where m is simply y/x.

Tags

CCSS.8.F.B.4

Answer explanation

Replace x with -6 and type in your calculator.

Tags

CCSS.6.EE.C.9