Direct Variation

y = -3x; y = -18

If y = -18 when x = 6, write the direct variation equation and find y when x = 6.

y = 0.5x; y = 10

If y = -7 when x = -14, write the direct variation equation and find y when x = 20.

y = 5x; y = 100

If y = 2.5 when x = 0.5, write the direct variation equation and find y when x = 20.

y = 4.5x; x = 10

If y = 27 when x = 6, write the direct variation equation and find x when y = 45.

y = 6x; x = 7

If y = 36 when x = 6, write the direct variation equation and find x when y = 42.

y = 1/3x; y = -8

If y = 4 when x = 12, write the direct variation equation and find y when x = -24.

y = 2x; y = 10

If y = 8 when x = 4, write the direct variation equation and find y when x = 5.

y = 3/2

If y varies directly with x, write an equation for the direct variation. Then find each value. Find y when x = 1, if y = 3 when x = 2.

NO

Is this proportional? YES or NO If yes what is the direct variation?

k = $33.75

Jerry rents snowmobiles to tourists. He charges $135 for 4 hours and $202.50 for 6 hours. If the cost varies directly with amount of hours find k, the hourly rate Jerry charges to rent a snowmobile?

y = 1.05x

The number of laps a swimmer swims, y, varies directly with the number of minutes spent swimming, x. In 50 minutes, the swimmer swims 52.5 laps. Write a direct variation equation

k = 1.5

What is the constant of proportionality? (type k = ___)

y = -1/4x; x = -80

If x = -16 when y = 4, write the direct variation equation and find x when y = 20.

y = -1/3x; y = -2

If x = -18 when y = 6, write the direct variation equation and find y when x = 6.

y = 2x; y = 40

If x = -7 when y = -14, write the direct variation equation and find y when x = 20.

y = 1/5x; y = 4

If x = 2.5 when y = 0.5, write the direct variation equation and find y when x = 20.

y = 1/6x; x = 252

If x = 36 when y = 6, write the direct variation equation and find x when y = 42.

y = 3x; y = -72

If x = 4 when y = 12, write the direct variation equation and find y when x = -24.

y = 0.5x; y = 2.5

If x = 8 when y = 4, write the direct variation equation and find y when x = 5.

y = -4x; x = -5

If y = -16 when x = 4, write the direct variation equation and find x when y = 20.