Question

What is answer to 12=4x what is x

Answer 1

12 = 4 x / / / Divide each side by 4. / / / 3 = x .

Answer 2

Division Property of Equality.
Always use opposite operation with side that contains variable.

Isolate variable.
Divide 4 by 4 to get it by itself.

Now do the same to other side.
$12\div4=3\\x=3$