(x)/(12) = (3)/(9) Use a proportion. Find missing value.

Question

`(x)/(12) = (3)/(9) Use a proportion. Find missing value.`

Answer 1

`x=4`

Explanation:

Cross-multiply to simplify:

`(x)/(12)=(3)/(9),\\9x=12\cdot 3,\\9x=36`

Divide both sides by 4 to isolate
`x`:

`x=(36)/(9)=\boxed{4}`