36r^2+39r-105=

Solution for 36r^2+39r-105= equation:

Simplifying
36r2 + 39r + -105 = 0

Reorder the terms:
-105 + 39r + 36r2 = 0

Solving
-105 + 39r + 36r2 = 0

Solving for variable 'r'.

Factor out the Greatest Common Factor (GCF), '3'.
3(-35 + 13r + 12r2) = 0

Factor a trinomial.
3((-7 + -3r)(5 + -4r)) = 0

Ignore the factor 3.
Subproblem 1
Set the factor '(-7 + -3r)' equal to zero and attempt to solve:

Simplifying
-7 + -3r = 0

Solving
-7 + -3r = 0

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

Add '7' to each side of the equation.
-7 + 7 + -3r = 0 + 7

Combine like terms: -7 + 7 = 0
0 + -3r = 0 + 7
-3r = 0 + 7

Combine like terms: 0 + 7 = 7
-3r = 7

Divide each side by '-3'.
r = -2.333333333

Simplifying
r = -2.333333333
Subproblem 2
Set the factor '(5 + -4r)' equal to zero and attempt to solve:

Simplifying
5 + -4r = 0

Solving
5 + -4r = 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 + -4r = 0 + -5

Combine like terms: 5 + -5 = 0
0 + -4r = 0 + -5
-4r = 0 + -5

Combine like terms: 0 + -5 = -5
-4r = -5

Divide each side by '-4'.
r = 1.25

Simplifying
r = 1.25
Solution
r = {-2.333333333, 1.25}