55r^2+13r-12=

Solution for 55r^2+13r-12= equation:

Simplifying
55r2 + 13r + -12 = 0

Reorder the terms:
-12 + 13r + 55r2 = 0

Solving
-12 + 13r + 55r2 = 0

Solving for variable 'r'.

Factor a trinomial.
(-3 + -5r)(4 + -11r) = 0

Subproblem 1
Set the factor '(-3 + -5r)' equal to zero and attempt to solve:

Simplifying
-3 + -5r = 0

Solving
-3 + -5r = 0

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

Add '3' to each side of the equation.
-3 + 3 + -5r = 0 + 3

Combine like terms: -3 + 3 = 0
0 + -5r = 0 + 3
-5r = 0 + 3

Combine like terms: 0 + 3 = 3
-5r = 3

Divide each side by '-5'.
r = -0.6

Simplifying
r = -0.6
Subproblem 2
Set the factor '(4 + -11r)' equal to zero and attempt to solve:

Simplifying
4 + -11r = 0

Solving
4 + -11r = 0

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

Add '-4' to each side of the equation.
4 + -4 + -11r = 0 + -4

Combine like terms: 4 + -4 = 0
0 + -11r = 0 + -4
-11r = 0 + -4

Combine like terms: 0 + -4 = -4
-11r = -4

Divide each side by '-11'.
r = 0.3636363636

Simplifying
r = 0.3636363636
Solution
r = {-0.6, 0.3636363636}