Direct and inverse variation

Which equation represents direct variation?

Which equation represents inverse variation?

• Direct

• Inverse

• Neither

If y varies directly with x, and the constant of variation is 4, which equation represents this relationship?

If y varies directly with x and y = 12 when x = 3, what is the value of y when x = 18?

• 0.25

• 4

• 4.5

• 72

If y varies inversely with x and y = 8 when x = 4, what is the value of y when x = 16?

• 2

• 4

• 32

• 64

If y varies inversely with x and y = 15 when x = 2, what is the value of x when y = 10?

• 3

• 300

• 30

Is this a direct variation?
y=2x

• yes
• no

Is this a direct variation?  y =2x + 1

• Yes
• No

Is this a direct variation?

• yes
• no