t^2+21t+20=0

Solution for t^2+21t+20=0 equation:

Simplifying
t2 + 21t + 20 = 0

Reorder the terms:
20 + 21t + t2 = 0

Solving
20 + 21t + t2 = 0

Solving for variable 't'.

Factor a trinomial.
(20 + t)(1 + t) = 0

Subproblem 1
Set the factor '(20 + t)' equal to zero and attempt to solve:

Simplifying
20 + t = 0

Solving
20 + t = 0

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

Add '-20' to each side of the equation.
20 + -20 + t = 0 + -20

Combine like terms: 20 + -20 = 0
0 + t = 0 + -20
t = 0 + -20

Combine like terms: 0 + -20 = -20
t = -20

Simplifying
t = -20
Subproblem 2
Set the factor '(1 + t)' equal to zero and attempt to solve:

Simplifying
1 + t = 0

Solving
1 + t = 0

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

Add '-1' to each side of the equation.
1 + -1 + t = 0 + -1

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

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

Simplifying
t = -1
Solution
t = {-20, -1}