7x^2+21x-128=-2

Solution for 7x^2+21x-128=-2 equation:

Simplifying
7x2 + 21x + -128 = -2

Reorder the terms:
-128 + 21x + 7x2 = -2

Solving
-128 + 21x + 7x2 = -2

Solving for variable 'x'.

Reorder the terms:
-128 + 2 + 21x + 7x2 = -2 + 2

Combine like terms: -128 + 2 = -126
-126 + 21x + 7x2 = -2 + 2

Combine like terms: -2 + 2 = 0
-126 + 21x + 7x2 = 0

Factor out the Greatest Common Factor (GCF), '7'.
7(-18 + 3x + x2) = 0

Factor a trinomial.
7((-6 + -1x)(3 + -1x)) = 0

Ignore the factor 7.
Subproblem 1
Set the factor '(-6 + -1x)' equal to zero and attempt to solve:

Simplifying
-6 + -1x = 0

Solving
-6 + -1x = 0

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

Add '6' to each side of the equation.
-6 + 6 + -1x = 0 + 6

Combine like terms: -6 + 6 = 0
0 + -1x = 0 + 6
-1x = 0 + 6

Combine like terms: 0 + 6 = 6
-1x = 6

Divide each side by '-1'.
x = -6

Simplifying
x = -6
Subproblem 2
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
Solution
x = {-6, 3}