2(x^2+4x-21)-(x^2+7x)=168

Solution for 2(x^2+4x-21)-(x^2+7x)=168 equation:

Simplifying
2(x2 + 4x + -21) + -1(x2 + 7x) = 168

Reorder the terms:
2(-21 + 4x + x2) + -1(x2 + 7x) = 168
(-21 * 2 + 4x * 2 + x2 * 2) + -1(x2 + 7x) = 168
(-42 + 8x + 2x2) + -1(x2 + 7x) = 168

Reorder the terms:
-42 + 8x + 2x2 + -1(7x + x2) = 168
-42 + 8x + 2x2 + (7x * -1 + x2 * -1) = 168
-42 + 8x + 2x2 + (-7x + -1x2) = 168

Reorder the terms:
-42 + 8x + -7x + 2x2 + -1x2 = 168

Combine like terms: 8x + -7x = 1x
-42 + 1x + 2x2 + -1x2 = 168

Combine like terms: 2x2 + -1x2 = 1x2
-42 + 1x + 1x2 = 168

Solving
-42 + 1x + 1x2 = 168

Solving for variable 'x'.

Reorder the terms:
-42 + -168 + 1x + 1x2 = 168 + -168

Combine like terms: -42 + -168 = -210
-210 + 1x + 1x2 = 168 + -168

Combine like terms: 168 + -168 = 0
-210 + 1x + 1x2 = 0

Factor a trinomial.
(-15 + -1x)(14 + -1x) = 0

Subproblem 1
Set the factor '(-15 + -1x)' equal to zero and attempt to solve:

Simplifying
-15 + -1x = 0

Solving
-15 + -1x = 0

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

Add '15' to each side of the equation.
-15 + 15 + -1x = 0 + 15

Combine like terms: -15 + 15 = 0
0 + -1x = 0 + 15
-1x = 0 + 15

Combine like terms: 0 + 15 = 15
-1x = 15

Divide each side by '-1'.
x = -15

Simplifying
x = -15
Subproblem 2
Set the factor '(14 + -1x)' equal to zero and attempt to solve:

Simplifying
14 + -1x = 0

Solving
14 + -1x = 0

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

Add '-14' to each side of the equation.
14 + -14 + -1x = 0 + -14

Combine like terms: 14 + -14 = 0
0 + -1x = 0 + -14
-1x = 0 + -14

Combine like terms: 0 + -14 = -14
-1x = -14

Divide each side by '-1'.
x = 14

Simplifying
x = 14
Solution
x = {-15, 14}