81=-12t+5t^2

Solution for 81=-12t+5t^2 equation:

Simplifying
81 = -12t + 5t2

Solving
81 = -12t + 5t2

Solving for variable 't'.

Reorder the terms:
81 + 12t + -5t2 = -12t + 12t + 5t2 + -5t2

Combine like terms: -12t + 12t = 0
81 + 12t + -5t2 = 0 + 5t2 + -5t2
81 + 12t + -5t2 = 5t2 + -5t2

Combine like terms: 5t2 + -5t2 = 0
81 + 12t + -5t2 = 0

Factor a trinomial.
(27 + -5t)(3 + t) = 0

Subproblem 1
Set the factor '(27 + -5t)' equal to zero and attempt to solve:

Simplifying
27 + -5t = 0

Solving
27 + -5t = 0

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

Add '-27' to each side of the equation.
27 + -27 + -5t = 0 + -27

Combine like terms: 27 + -27 = 0
0 + -5t = 0 + -27
-5t = 0 + -27

Combine like terms: 0 + -27 = -27
-5t = -27

Divide each side by '-5'.
t = 5.4

Simplifying
t = 5.4
Subproblem 2
Set the factor '(3 + t)' equal to zero and attempt to solve:

Simplifying
3 + t = 0

Solving
3 + t = 0

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

Add '-3' to each side of the equation.
3 + -3 + t = 0 + -3

Combine like terms: 3 + -3 = 0
0 + t = 0 + -3
t = 0 + -3

Combine like terms: 0 + -3 = -3
t = -3

Simplifying
t = -3
Solution
t = {5.4, -3}