h^2+20h-21=0

Solution for h^2+20h-21=0 equation:

Simplifying
h2 + 20h + -21 = 0

Reorder the terms:
-21 + 20h + h2 = 0

Solving
-21 + 20h + h2 = 0

Solving for variable 'h'.

Factor a trinomial.
(-21 + -1h)(1 + -1h) = 0

Subproblem 1
Set the factor '(-21 + -1h)' equal to zero and attempt to solve:

Simplifying
-21 + -1h = 0

Solving
-21 + -1h = 0

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

Add '21' to each side of the equation.
-21 + 21 + -1h = 0 + 21

Combine like terms: -21 + 21 = 0
0 + -1h = 0 + 21
-1h = 0 + 21

Combine like terms: 0 + 21 = 21
-1h = 21

Divide each side by '-1'.
h = -21

Simplifying
h = -21
Subproblem 2
Set the factor '(1 + -1h)' equal to zero and attempt to solve:

Simplifying
1 + -1h = 0

Solving
1 + -1h = 0

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

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

Combine like terms: 1 + -1 = 0
0 + -1h = 0 + -1
-1h = 0 + -1

Combine like terms: 0 + -1 = -1
-1h = -1

Divide each side by '-1'.
h = 1

Simplifying
h = 1
Solution
h = {-21, 1}