Question

If y varies directly as x and y = 24 when x = -3, find the constant of variation k

and then determine y when x = 12.

Answer 1

I. k = -8

II. y = -96

Explanation:

Given the mathematical expression and data;

y = 24

x = -3

y = kx (y varies directly as x).

To find the constant of proportionality k;

y = kx

Substituting the values into the expression, we have;

24 = k(-3)

24 = -3k

k = -24/3

k = -8

Next, to find the value of y when x = 12

y = kx

Substituting the values, we have;

y = -8 * 12

y = -96