-r^2-5r+66=

Solution for -r^2-5r+66= equation:

Simplifying
-1r2 + -5r + 66 = 0

Reorder the terms:
66 + -5r + -1r2 = 0

Solving
66 + -5r + -1r2 = 0

Solving for variable 'r'.

Factor a trinomial.
(6 + -1r)(11 + r) = 0

Subproblem 1
Set the factor '(6 + -1r)' equal to zero and attempt to solve:

Simplifying
6 + -1r = 0

Solving
6 + -1r = 0

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

Add '-6' to each side of the equation.
6 + -6 + -1r = 0 + -6

Combine like terms: 6 + -6 = 0
0 + -1r = 0 + -6
-1r = 0 + -6

Combine like terms: 0 + -6 = -6
-1r = -6

Divide each side by '-1'.
r = 6

Simplifying
r = 6
Subproblem 2
Set the factor '(11 + r)' equal to zero and attempt to solve:

Simplifying
11 + r = 0

Solving
11 + r = 0

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

Add '-11' to each side of the equation.
11 + -11 + r = 0 + -11

Combine like terms: 11 + -11 = 0
0 + r = 0 + -11
r = 0 + -11

Combine like terms: 0 + -11 = -11
r = -11

Simplifying
r = -11
Solution
r = {6, -11}