y^2+22y+21=0

Solution for y^2+22y+21=0 equation:

Simplifying
y2 + 22y + 21 = 0

Reorder the terms:
21 + 22y + y2 = 0

Solving
21 + 22y + y2 = 0

Solving for variable 'y'.

Factor a trinomial.
(21 + y)(1 + y) = 0

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

Simplifying
21 + y = 0

Solving
21 + y = 0

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

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

Combine like terms: 21 + -21 = 0
0 + y = 0 + -21
y = 0 + -21

Combine like terms: 0 + -21 = -21
y = -21

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

Simplifying
1 + y = 0

Solving
1 + y = 0

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

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

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

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

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