Question

Y varies directly as x, if y=9 x=3 find x when y=-27

Answer 1

x = -9

Explanation:

Standard equation of direct variation:

y = kx

We need to find k.

We use the given point.

When x = 3, y = 9.

9 = k * 3

k = 3

Our equation is

y = 3x

Now we find x when y = -27.

y = 3x

-27 = 3x

x = -9