Inverse Variation and Direct Variation

y varies directly as x, if y=12 when x=5, find y when x=3

• 36/5
• 15/12
• 12/5
• 12/15

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

• -16
• 16
• -9
• 9

Which equation represents an inverse variation?

• y = 40/x
• y = 40x
• y/x = 40
• x = y/40

Which equation below represents a direct variation?

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

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

• x
• y
• 400
• Not enough information given