y^2-80y-81=0

Solution for y^2-80y-81=0 equation:

Simplifying
y2 + -80y + -81 = 0

Reorder the terms:
-81 + -80y + y2 = 0

Solving
-81 + -80y + y2 = 0

Solving for variable 'y'.

Factor a trinomial.
(-1 + -1y)(81 + -1y) = 0

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

Simplifying
-1 + -1y = 0

Solving
-1 + -1y = 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 + -1y = 0 + 1

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

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

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

Simplifying
y = -1
Subproblem 2
Set the factor '(81 + -1y)' equal to zero and attempt to solve:

Simplifying
81 + -1y = 0

Solving
81 + -1y = 0

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

Add '-81' to each side of the equation.
81 + -81 + -1y = 0 + -81

Combine like terms: 81 + -81 = 0
0 + -1y = 0 + -81
-1y = 0 + -81

Combine like terms: 0 + -81 = -81
-1y = -81

Divide each side by '-1'.
y = 81

Simplifying
y = 81
Solution
y = {-1, 81}