8h^2-2h=21

Solution for 8h^2-2h=21 equation:

Simplifying
8h2 + -2h = 21

Reorder the terms:
-2h + 8h2 = 21

Solving
-2h + 8h2 = 21

Solving for variable 'h'.

Reorder the terms:
-21 + -2h + 8h2 = 21 + -21

Combine like terms: 21 + -21 = 0
-21 + -2h + 8h2 = 0

Factor a trinomial.
(-3 + -2h)(7 + -4h) = 0

Subproblem 1
Set the factor '(-3 + -2h)' equal to zero and attempt to solve:

Simplifying
-3 + -2h = 0

Solving
-3 + -2h = 0

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

Add '3' to each side of the equation.
-3 + 3 + -2h = 0 + 3

Combine like terms: -3 + 3 = 0
0 + -2h = 0 + 3
-2h = 0 + 3

Combine like terms: 0 + 3 = 3
-2h = 3

Divide each side by '-2'.
h = -1.5

Simplifying
h = -1.5
Subproblem 2
Set the factor '(7 + -4h)' equal to zero and attempt to solve:

Simplifying
7 + -4h = 0

Solving
7 + -4h = 0

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

Add '-7' to each side of the equation.
7 + -7 + -4h = 0 + -7

Combine like terms: 7 + -7 = 0
0 + -4h = 0 + -7
-4h = 0 + -7

Combine like terms: 0 + -7 = -7
-4h = -7

Divide each side by '-4'.
h = 1.75

Simplifying
h = 1.75
Solution
h = {-1.5, 1.75}