4x^2-8x+16=21

Solution for 4x^2-8x+16=21 equation:

Simplifying
4x2 + -8x + 16 = 21

Reorder the terms:
16 + -8x + 4x2 = 21

Solving
16 + -8x + 4x2 = 21

Solving for variable 'x'.

Reorder the terms:
16 + -21 + -8x + 4x2 = 21 + -21

Combine like terms: 16 + -21 = -5
-5 + -8x + 4x2 = 21 + -21

Combine like terms: 21 + -21 = 0
-5 + -8x + 4x2 = 0

Factor a trinomial.
(-1 + -2x)(5 + -2x) = 0

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

Simplifying
-1 + -2x = 0

Solving
-1 + -2x = 0

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

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

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

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

Divide each side by '-2'.
x = -0.5

Simplifying
x = -0.5
Subproblem 2
Set the factor '(5 + -2x)' equal to zero and attempt to solve:

Simplifying
5 + -2x = 0

Solving
5 + -2x = 0

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

Add '-5' to each side of the equation.
5 + -5 + -2x = 0 + -5

Combine like terms: 5 + -5 = 0
0 + -2x = 0 + -5
-2x = 0 + -5

Combine like terms: 0 + -5 = -5
-2x = -5

Divide each side by '-2'.
x = 2.5

Simplifying
x = 2.5
Solution
x = {-0.5, 2.5}