-3r^2+30r-72=

Solution for -3r^2+30r-72= equation:

Simplifying
-3r2 + 30r + -72 = 0

Reorder the terms:
-72 + 30r + -3r2 = 0

Solving
-72 + 30r + -3r2 = 0

Solving for variable 'r'.

Factor out the Greatest Common Factor (GCF), '3'.
3(-24 + 10r + -1r2) = 0

Factor a trinomial.
3((-6 + r)(4 + -1r)) = 0

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

Simplifying
-6 + r = 0

Solving
-6 + r = 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 + r = 0 + 6

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

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

Simplifying
r = 6
Subproblem 2
Set the factor '(4 + -1r)' equal to zero and attempt to solve:

Simplifying
4 + -1r = 0

Solving
4 + -1r = 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 + -1r = 0 + -4

Combine like terms: 4 + -4 = 0
0 + -1r = 0 + -4
-1r = 0 + -4

Combine like terms: 0 + -4 = -4
-1r = -4

Divide each side by '-1'.
r = 4

Simplifying
r = 4
Solution
r = {6, 4}