what is the direct variation of x=2 when y=10 find x when y=20

Question

what is the direct variation of x=2 when y=10 and find x when y=20

Answer 1

Direct variation y = kx

Given numbers form a ratio expressed as y/x = 10/2

To find x when y = 20

We set up another ratio is 20/x.

By the definition both ratios are equal.

10/2 = 20/x

5 = 20/x

Cross multiplication.

5x = 20

Divide to each side by 5.

5x/5 = 20/5

x = 4