(7x-7)(9x+9)=0

Solution for (7x-7)(9x+9)=0 equation:

Simplifying
(7x + -7)(9x + 9) = 0

Reorder the terms:
(-7 + 7x)(9x + 9) = 0

Reorder the terms:
(-7 + 7x)(9 + 9x) = 0

Multiply (-7 + 7x) * (9 + 9x)
(-7(9 + 9x) + 7x * (9 + 9x)) = 0
((9 * -7 + 9x * -7) + 7x * (9 + 9x)) = 0
((-63 + -63x) + 7x * (9 + 9x)) = 0
(-63 + -63x + (9 * 7x + 9x * 7x)) = 0
(-63 + -63x + (63x + 63x2)) = 0

Combine like terms: -63x + 63x = 0
(-63 + 0 + 63x2) = 0
(-63 + 63x2) = 0

Solving
-63 + 63x2 = 0

Solving for variable 'x'.

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

Add '63' to each side of the equation.
-63 + 63 + 63x2 = 0 + 63

Combine like terms: -63 + 63 = 0
0 + 63x2 = 0 + 63
63x2 = 0 + 63

Combine like terms: 0 + 63 = 63
63x2 = 63

Divide each side by '63'.
x2 = 1

Simplifying
x2 = 1

Take the square root of each side:
x = {-1, 1}