-r^2-8r+65=

Solution for -r^2-8r+65= equation:

Simplifying
-1r2 + -8r + 65 = 0

Reorder the terms:
65 + -8r + -1r2 = 0

Solving
65 + -8r + -1r2 = 0

Solving for variable 'r'.

Factor a trinomial.
(5 + -1r)(13 + r) = 0

Subproblem 1
Set the factor '(5 + -1r)' equal to zero and attempt to solve:

Simplifying
5 + -1r = 0

Solving
5 + -1r = 0

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

Add '-5' to each side of the equation.
5 + -5 + -1r = 0 + -5

Combine like terms: 5 + -5 = 0
0 + -1r = 0 + -5
-1r = 0 + -5

Combine like terms: 0 + -5 = -5
-1r = -5

Divide each side by '-1'.
r = 5

Simplifying
r = 5
Subproblem 2
Set the factor '(13 + r)' equal to zero and attempt to solve:

Simplifying
13 + r = 0

Solving
13 + r = 0

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

Add '-13' to each side of the equation.
13 + -13 + r = 0 + -13

Combine like terms: 13 + -13 = 0
0 + r = 0 + -13
r = 0 + -13

Combine like terms: 0 + -13 = -13
r = -13

Simplifying
r = -13
Solution
r = {5, -13}