36=(3r+3)(r-3)

Solution for 36=(3r+3)(r-3) equation:

Simplifying
36 = (3r + 3)(r + -3)

Reorder the terms:
36 = (3 + 3r)(r + -3)

Reorder the terms:
36 = (3 + 3r)(-3 + r)

Multiply (3 + 3r) * (-3 + r)
36 = (3(-3 + r) + 3r * (-3 + r))
36 = ((-3 * 3 + r * 3) + 3r * (-3 + r))
36 = ((-9 + 3r) + 3r * (-3 + r))
36 = (-9 + 3r + (-3 * 3r + r * 3r))
36 = (-9 + 3r + (-9r + 3r2))

Combine like terms: 3r + -9r = -6r
36 = (-9 + -6r + 3r2)

Solving
36 = -9 + -6r + 3r2

Solving for variable 'r'.

Combine like terms: 36 + 9 = 45
45 + 6r + -3r2 = -9 + -6r + 3r2 + 9 + 6r + -3r2

Reorder the terms:
45 + 6r + -3r2 = -9 + 9 + -6r + 6r + 3r2 + -3r2

Combine like terms: -9 + 9 = 0
45 + 6r + -3r2 = 0 + -6r + 6r + 3r2 + -3r2
45 + 6r + -3r2 = -6r + 6r + 3r2 + -3r2

Combine like terms: -6r + 6r = 0
45 + 6r + -3r2 = 0 + 3r2 + -3r2
45 + 6r + -3r2 = 3r2 + -3r2

Combine like terms: 3r2 + -3r2 = 0
45 + 6r + -3r2 = 0

Factor out the Greatest Common Factor (GCF), '3'.
3(15 + 2r + -1r2) = 0

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

Ignore the factor 3.
Subproblem 1
Set the factor '(5 + -1r)' equal to zero and attempt to solve:

Simplifying
5 + -1r = 0

Solving
5 + -1r = 0

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

Add '-5' to each side of the equation.
5 + -5 + -1r = 0 + -5

Combine like terms: 5 + -5 = 0
0 + -1r = 0 + -5
-1r = 0 + -5

Combine like terms: 0 + -5 = -5
-1r = -5

Divide each side by '-1'.
r = 5

Simplifying
r = 5
Subproblem 2
Set the factor '(3 + r)' equal to zero and attempt to solve:

Simplifying
3 + r = 0

Solving
3 + r = 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 + r = 0 + -3

Combine like terms: 3 + -3 = 0
0 + r = 0 + -3
r = 0 + -3

Combine like terms: 0 + -3 = -3
r = -3

Simplifying
r = -3
Solution
r = {5, -3}