-15r^2+6r+9=0

Solution for -15r^2+6r+9=0 equation:

Simplifying
-15r2 + 6r + 9 = 0

Reorder the terms:
9 + 6r + -15r2 = 0

Solving
9 + 6r + -15r2 = 0

Solving for variable 'r'.

Factor out the Greatest Common Factor (GCF), '3'.
3(3 + 2r + -5r2) = 0

Factor a trinomial.
3((1 + -1r)(3 + 5r)) = 0

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

Simplifying
1 + -1r = 0

Solving
1 + -1r = 0

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

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

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

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

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

Simplifying
r = 1
Subproblem 2
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
Solution
r = {1, -0.6}