r(r+6)-72=0

Solution for r(r+6)-72=0 equation:

Simplifying
r(r + 6) + -72 = 0

Reorder the terms:
r(6 + r) + -72 = 0
(6 * r + r * r) + -72 = 0
(6r + r2) + -72 = 0

Reorder the terms:
-72 + 6r + r2 = 0

Solving
-72 + 6r + r2 = 0

Solving for variable 'r'.

Factor a trinomial.
(-12 + -1r)(6 + -1r) = 0

Subproblem 1
Set the factor '(-12 + -1r)' equal to zero and attempt to solve:

Simplifying
-12 + -1r = 0

Solving
-12 + -1r = 0

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

Add '12' to each side of the equation.
-12 + 12 + -1r = 0 + 12

Combine like terms: -12 + 12 = 0
0 + -1r = 0 + 12
-1r = 0 + 12

Combine like terms: 0 + 12 = 12
-1r = 12

Divide each side by '-1'.
r = -12

Simplifying
r = -12
Subproblem 2
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
Solution
r = {-12, 6}