Question

Let x = 1/2 and y=2/3. If y varies directly as x. Find x when y =8

Answer 1

Direct variation is of the form y=kx, where k is the constant of variation.

In this case we are given a point (1/2, 2/3) so we can solve for k.

2/3=k/2 multiply both sides by 2

4/3=k, so our equation is:

y=4x/3, so when y=8

8=4x/3 multiply both sides by 3

24=4x divide both sides by 4

6=x