(9*9)+(12*12)=x*x

Solution for (9*9)+(12*12)=x*x equation:

Simplifying
(9 * 9) + (12 * 12) = x * x

Multiply 9 * 9
(81) + (12 * 12) = x * x
81 + (12 * 12) = x * x

Multiply 12 * 12
81 + (144) = x * x
81 + 144 = x * x

Combine like terms: 81 + 144 = 225
225 = x * x

Multiply x * x
225 = x2

Solving
225 = x2

Solving for variable 'x'.

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

Add '-1x2' to each side of the equation.
225 + -1x2 = x2 + -1x2

Combine like terms: x2 + -1x2 = 0
225 + -1x2 = 0

Add '-225' to each side of the equation.
225 + -225 + -1x2 = 0 + -225

Combine like terms: 225 + -225 = 0
0 + -1x2 = 0 + -225
-1x2 = 0 + -225

Combine like terms: 0 + -225 = -225
-1x2 = -225

Divide each side by '-1'.
x2 = 225

Simplifying
x2 = 225

Take the square root of each side:
x = {-15, 15}