2x^2-81=(x-9)(x+9)

Solution for 2x^2-81=(x-9)(x+9) equation:

Simplifying
2x2 + -81 = (x + -9)(x + 9)

Reorder the terms:
-81 + 2x2 = (x + -9)(x + 9)

Reorder the terms:
-81 + 2x2 = (-9 + x)(x + 9)

Reorder the terms:
-81 + 2x2 = (-9 + x)(9 + x)

Multiply (-9 + x) * (9 + x)
-81 + 2x2 = (-9(9 + x) + x(9 + x))
-81 + 2x2 = ((9 * -9 + x * -9) + x(9 + x))
-81 + 2x2 = ((-81 + -9x) + x(9 + x))
-81 + 2x2 = (-81 + -9x + (9 * x + x * x))
-81 + 2x2 = (-81 + -9x + (9x + x2))

Combine like terms: -9x + 9x = 0
-81 + 2x2 = (-81 + 0 + x2)
-81 + 2x2 = (-81 + x2)

Add '81' to each side of the equation.
-81 + 81 + 2x2 = -81 + 81 + x2

Combine like terms: -81 + 81 = 0
0 + 2x2 = -81 + 81 + x2
2x2 = -81 + 81 + x2

Combine like terms: -81 + 81 = 0
2x2 = 0 + x2
2x2 = x2

Solving
2x2 = 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.
2x2 + -1x2 = x2 + -1x2

Combine like terms: 2x2 + -1x2 = 1x2
1x2 = x2 + -1x2

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

Divide each side by '1'.
x2 = 0

Simplifying
x2 = 0

Take the square root of each side:
x = {0}