3r^2+15r=18

Solution for 3r^2+15r=18 equation:

Simplifying
3r2 + 15r = 18

Reorder the terms:
15r + 3r2 = 18

Solving
15r + 3r2 = 18

Solving for variable 'r'.

Reorder the terms:
-18 + 15r + 3r2 = 18 + -18

Combine like terms: 18 + -18 = 0
-18 + 15r + 3r2 = 0

Factor out the Greatest Common Factor (GCF), '3'.
3(-6 + 5r + r2) = 0

Factor a trinomial.
3((-6 + -1r)(1 + -1r)) = 0

Ignore the factor 3.
Subproblem 1
Set the factor '(-6 + -1r)' equal to zero and attempt to solve:

Simplifying
-6 + -1r = 0

Solving
-6 + -1r = 0

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

Add '6' to each side of the equation.
-6 + 6 + -1r = 0 + 6

Combine like terms: -6 + 6 = 0
0 + -1r = 0 + 6
-1r = 0 + 6

Combine like terms: 0 + 6 = 6
-1r = 6

Divide each side by '-1'.
r = -6

Simplifying
r = -6
Subproblem 2
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
Solution
r = {-6, 1}