(x-3)(x+3)=21x-63

Solution for (x-3)(x+3)=21x-63 equation:

Simplifying
(x + -3)(x + 3) = 21x + -63

Reorder the terms:
(-3 + x)(x + 3) = 21x + -63

Reorder the terms:
(-3 + x)(3 + x) = 21x + -63

Multiply (-3 + x) * (3 + x)
(-3(3 + x) + x(3 + x)) = 21x + -63
((3 * -3 + x * -3) + x(3 + x)) = 21x + -63
((-9 + -3x) + x(3 + x)) = 21x + -63
(-9 + -3x + (3 * x + x * x)) = 21x + -63
(-9 + -3x + (3x + x2)) = 21x + -63

Combine like terms: -3x + 3x = 0
(-9 + 0 + x2) = 21x + -63
(-9 + x2) = 21x + -63

Reorder the terms:
-9 + x2 = -63 + 21x

Solving
-9 + x2 = -63 + 21x

Solving for variable 'x'.

Reorder the terms:
-9 + 63 + -21x + x2 = -63 + 21x + 63 + -21x

Combine like terms: -9 + 63 = 54
54 + -21x + x2 = -63 + 21x + 63 + -21x

Reorder the terms:
54 + -21x + x2 = -63 + 63 + 21x + -21x

Combine like terms: -63 + 63 = 0
54 + -21x + x2 = 0 + 21x + -21x
54 + -21x + x2 = 21x + -21x

Combine like terms: 21x + -21x = 0
54 + -21x + x2 = 0

Factor a trinomial.
(3 + -1x)(18 + -1x) = 0

Subproblem 1
Set the factor '(3 + -1x)' equal to zero and attempt to solve:

Simplifying
3 + -1x = 0

Solving
3 + -1x = 0

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

Add '-3' to each side of the equation.
3 + -3 + -1x = 0 + -3

Combine like terms: 3 + -3 = 0
0 + -1x = 0 + -3
-1x = 0 + -3

Combine like terms: 0 + -3 = -3
-1x = -3

Divide each side by '-1'.
x = 3

Simplifying
x = 3
Subproblem 2
Set the factor '(18 + -1x)' equal to zero and attempt to solve:

Simplifying
18 + -1x = 0

Solving
18 + -1x = 0

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

Add '-18' to each side of the equation.
18 + -18 + -1x = 0 + -18

Combine like terms: 18 + -18 = 0
0 + -1x = 0 + -18
-1x = 0 + -18

Combine like terms: 0 + -18 = -18
-1x = -18

Divide each side by '-1'.
x = 18

Simplifying
x = 18
Solution
x = {3, 18}