(6-x)(6+x)=x(9-x)

Solution for (6-x)(6+x)=x(9-x) equation:

Simplifying
(6 + -1x)(6 + x) = x(9 + -1x)

Multiply (6 + -1x) * (6 + x)
(6(6 + x) + -1x * (6 + x)) = x(9 + -1x)
((6 * 6 + x * 6) + -1x * (6 + x)) = x(9 + -1x)
((36 + 6x) + -1x * (6 + x)) = x(9 + -1x)
(36 + 6x + (6 * -1x + x * -1x)) = x(9 + -1x)
(36 + 6x + (-6x + -1x2)) = x(9 + -1x)

Combine like terms: 6x + -6x = 0
(36 + 0 + -1x2) = x(9 + -1x)
(36 + -1x2) = x(9 + -1x)
36 + -1x2 = (9 * x + -1x * x)
36 + -1x2 = (9x + -1x2)

Add 'x2' to each side of the equation.
36 + -1x2 + x2 = 9x + -1x2 + x2

Combine like terms: -1x2 + x2 = 0
36 + 0 = 9x + -1x2 + x2
36 = 9x + -1x2 + x2

Combine like terms: -1x2 + x2 = 0
36 = 9x + 0
36 = 9x

Solving
36 = 9x

Solving for variable 'x'.

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

Add '-9x' to each side of the equation.
36 + -9x = 9x + -9x

Combine like terms: 9x + -9x = 0
36 + -9x = 0

Add '-36' to each side of the equation.
36 + -36 + -9x = 0 + -36

Combine like terms: 36 + -36 = 0
0 + -9x = 0 + -36
-9x = 0 + -36

Combine like terms: 0 + -36 = -36
-9x = -36

Divide each side by '-9'.
x = 4

Simplifying
x = 4