If y varies directly with x, write an equation for the direct variation. Then find each value.

1. If y = - 12 when x=9, find y when x = - 4

2. Find y when x=10 if y = 8 when x = 20

3. If y = - 6 when x = - 14, find x when y = - 4

Question

Mathematics

Alessandra Beasley

23 June, 09:02

If y varies directly with x, write an equation for the direct variation. Then find each value.

1. If y = - 12 when x=9, find y when x = - 4

2. Find y when x=10 if y = 8 when x = 20

3. If y = - 6 when x = - 14, find x when y = - 4

+1

Answers (1)

Know the Answer?

Matthias Moore · Answer 1

1)

y = kx

-12 = k (9)

k = - 4/3

y = (-4/3) (-4)

y = 16/3

2)

y = kx

8 = 20k

k = 2/5

y = (2/5) (10)

y = 4

3)

y = kx

-6 = k (-14)

k = 3/7

-4 = (3/7) x

-4 (7/3) = x

x = - 28/3

If y varies directly with x, write an equation for the direct variation. Then find each value.1. If y = - 12 when x=9, find y when x = - 42. Find y when x=10 if y = 8 when x = 203. If y = - 6 when x = - 14, find x when y = - 4

If y varies directly with x, write an equation for the direct variation. Then find each value.

1. If y = - 12 when x=9, find y when x = - 4

2. Find y when x=10 if y = 8 when x = 20

3. If y = - 6 when x = - 14, find x when y = - 4