t^2-22t+21=0

Solution for t^2-22t+21=0 equation:

Simplifying
t2 + -22t + 21 = 0

Reorder the terms:
21 + -22t + t2 = 0

Solving
21 + -22t + t2 = 0

Solving for variable 't'.

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

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

Simplifying
1 + -1t = 0

Solving
1 + -1t = 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 + -1t = 0 + -1

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

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

Divide each side by '-1'.
t = 1

Simplifying
t = 1
Subproblem 2
Set the factor '(21 + -1t)' equal to zero and attempt to solve:

Simplifying
21 + -1t = 0

Solving
21 + -1t = 0

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

Add '-21' to each side of the equation.
21 + -21 + -1t = 0 + -21

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

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

Divide each side by '-1'.
t = 21

Simplifying
t = 21
Solution
t = {1, 21}