If y varied directly as x and y=18 when x=15, find y when x =20

Answer 1

When Y varies directly with X, the format of the equation will look like this:

Y = kX (k will be a constant).

Now, we just have to find the value of K with the values they have already given to us.

18 = k * 15

k = 18/15 === 6/5

Let X = 20

y = ( 6 / 5 ) * 20

y = 24

Hope this helps!

Answer 2

You can set up a proportion to solve for the unknown y.