-y^2-y=-12

Solution for -y^2-y=-12 equation:

Simplifying
-1y2 + -1y = -12

Reorder the terms:
-1y + -1y2 = -12

Solving
-1y + -1y2 = -12

Solving for variable 'y'.

Reorder the terms:
12 + -1y + -1y2 = -12 + 12

Combine like terms: -12 + 12 = 0
12 + -1y + -1y2 = 0

Factor a trinomial.
(3 + -1y)(4 + y) = 0

Subproblem 1
Set the factor '(3 + -1y)' equal to zero and attempt to solve:

Simplifying
3 + -1y = 0

Solving
3 + -1y = 0

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

Add '-3' to each side of the equation.
3 + -3 + -1y = 0 + -3

Combine like terms: 3 + -3 = 0
0 + -1y = 0 + -3
-1y = 0 + -3

Combine like terms: 0 + -3 = -3
-1y = -3

Divide each side by '-1'.
y = 3

Simplifying
y = 3
Subproblem 2
Set the factor '(4 + y)' equal to zero and attempt to solve:

Simplifying
4 + y = 0

Solving
4 + y = 0

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

Add '-4' to each side of the equation.
4 + -4 + y = 0 + -4

Combine like terms: 4 + -4 = 0
0 + y = 0 + -4
y = 0 + -4

Combine like terms: 0 + -4 = -4
y = -4

Simplifying
y = -4
Solution
y = {3, -4}