Question

If y varies directly as x and y=12 when x=4, what is the value of y when x=12 ?

Answer 1

y = 36 when x = 12

Explanation:

General equation for direct variation:

The general equation for direct variation is given by:

y = kx, where

• k is the constant of proportionality.

Finding k:

• We can first find k by substituting 12 for y and 4 for x.

Finding k will allow to create an equation relating y and x:

(12 = 4k) / 4

3 = k

Thus, y = 3x is the equation relating y and x.

Finding y when x = 12:

Now we can find y when x = 12 by substituting 12 for x in y = 3x:

y = 3(12)

y = 36

Thus, 36 is the value of y when x = 12.