2(x^2-8x)+3=-21

Solution for 2(x^2-8x)+3=-21 equation:

Simplifying
2(x2 + -8x) + 3 = -21

Reorder the terms:
2(-8x + x2) + 3 = -21
(-8x * 2 + x2 * 2) + 3 = -21
(-16x + 2x2) + 3 = -21

Reorder the terms:
3 + -16x + 2x2 = -21

Solving
3 + -16x + 2x2 = -21

Solving for variable 'x'.

Reorder the terms:
3 + 21 + -16x + 2x2 = -21 + 21

Combine like terms: 3 + 21 = 24
24 + -16x + 2x2 = -21 + 21

Combine like terms: -21 + 21 = 0
24 + -16x + 2x2 = 0

Factor out the Greatest Common Factor (GCF), '2'.
2(12 + -8x + x2) = 0

Factor a trinomial.
2((2 + -1x)(6 + -1x)) = 0

Ignore the factor 2.
Subproblem 1
Set the factor '(2 + -1x)' equal to zero and attempt to solve:

Simplifying
2 + -1x = 0

Solving
2 + -1x = 0

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

Add '-2' to each side of the equation.
2 + -2 + -1x = 0 + -2

Combine like terms: 2 + -2 = 0
0 + -1x = 0 + -2
-1x = 0 + -2

Combine like terms: 0 + -2 = -2
-1x = -2

Divide each side by '-1'.
x = 2

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