-5r^2-12r-4=0

Solution for -5r^2-12r-4=0 equation:

Simplifying
-5r2 + -12r + -4 = 0

Reorder the terms:
-4 + -12r + -5r2 = 0

Solving
-4 + -12r + -5r2 = 0

Solving for variable 'r'.

Factor out the Greatest Common Factor (GCF), '-1'.
-1(4 + 12r + 5r2) = 0

Factor a trinomial.
-1((2 + r)(2 + 5r)) = 0

Ignore the factor -1.
Subproblem 1
Set the factor '(2 + r)' equal to zero and attempt to solve:

Simplifying
2 + r = 0

Solving
2 + r = 0

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

Add '-2' to each side of the equation.
2 + -2 + r = 0 + -2

Combine like terms: 2 + -2 = 0
0 + r = 0 + -2
r = 0 + -2

Combine like terms: 0 + -2 = -2
r = -2

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

Simplifying
2 + 5r = 0

Solving
2 + 5r = 0

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

Add '-2' to each side of the equation.
2 + -2 + 5r = 0 + -2

Combine like terms: 2 + -2 = 0
0 + 5r = 0 + -2
5r = 0 + -2

Combine like terms: 0 + -2 = -2
5r = -2

Divide each side by '5'.
r = -0.4

Simplifying
r = -0.4
Solution
r = {-2, -0.4}