72-(12-9)=x

Solution for 72-(12-9)=x equation:

Simplifying
72 + -1(12 + -9) = x

Combine like terms: 12 + -9 = 3
72 + -1(3) = x

Multiply -1 * 3
72 + -3 = x

Combine like terms: 72 + -3 = 69
69 = x

Solving
69 = x

Solving for variable 'x'.

Move all terms containing x to the left, all other terms to the right.

Add '-1x' to each side of the equation.
69 + -1x = x + -1x

Combine like terms: x + -1x = 0
69 + -1x = 0

Add '-69' to each side of the equation.
69 + -69 + -1x = 0 + -69

Combine like terms: 69 + -69 = 0
0 + -1x = 0 + -69
-1x = 0 + -69

Combine like terms: 0 + -69 = -69
-1x = -69

Divide each side by '-1'.
x = 69

Simplifying
x = 69