r^2-4r-37=8

Solution for r^2-4r-37=8 equation:

Simplifying
r2 + -4r + -37 = 8

Reorder the terms:
-37 + -4r + r2 = 8

Solving
-37 + -4r + r2 = 8

Solving for variable 'r'.

Reorder the terms:
-37 + -8 + -4r + r2 = 8 + -8

Combine like terms: -37 + -8 = -45
-45 + -4r + r2 = 8 + -8

Combine like terms: 8 + -8 = 0
-45 + -4r + r2 = 0

Factor a trinomial.
(-5 + -1r)(9 + -1r) = 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 '(9 + -1r)' equal to zero and attempt to solve:

Simplifying
9 + -1r = 0

Solving
9 + -1r = 0

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

Add '-9' to each side of the equation.
9 + -9 + -1r = 0 + -9

Combine like terms: 9 + -9 = 0
0 + -1r = 0 + -9
-1r = 0 + -9

Combine like terms: 0 + -9 = -9
-1r = -9

Divide each side by '-1'.
r = 9

Simplifying
r = 9
Solution
r = {-5, 9}