g^2+20g-21=0

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

Simplifying
g2 + 20g + -21 = 0

Reorder the terms:
-21 + 20g + g2 = 0

Solving
-21 + 20g + g2 = 0

Solving for variable 'g'.

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

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

Simplifying
-21 + -1g = 0

Solving
-21 + -1g = 0

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

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

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

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

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

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

Simplifying
1 + -1g = 0

Solving
1 + -1g = 0

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

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

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

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

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

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