r(r+3)=88

Solution for r(r+3)=88 equation:

Simplifying
r(r + 3) = 88

Reorder the terms:
r(3 + r) = 88
(3 * r + r * r) = 88
(3r + r2) = 88

Solving
3r + r2 = 88

Solving for variable 'r'.

Reorder the terms:
-88 + 3r + r2 = 88 + -88

Combine like terms: 88 + -88 = 0
-88 + 3r + r2 = 0

Factor a trinomial.
(-11 + -1r)(8 + -1r) = 0

Subproblem 1
Set the factor '(-11 + -1r)' equal to zero and attempt to solve:

Simplifying
-11 + -1r = 0

Solving
-11 + -1r = 0

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

Add '11' to each side of the equation.
-11 + 11 + -1r = 0 + 11

Combine like terms: -11 + 11 = 0
0 + -1r = 0 + 11
-1r = 0 + 11

Combine like terms: 0 + 11 = 11
-1r = 11

Divide each side by '-1'.
r = -11

Simplifying
r = -11
Subproblem 2
Set the factor '(8 + -1r)' equal to zero and attempt to solve:

Simplifying
8 + -1r = 0

Solving
8 + -1r = 0

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

Add '-8' to each side of the equation.
8 + -8 + -1r = 0 + -8

Combine like terms: 8 + -8 = 0
0 + -1r = 0 + -8
-1r = 0 + -8

Combine like terms: 0 + -8 = -8
-1r = -8

Divide each side by '-1'.
r = 8

Simplifying
r = 8
Solution
r = {-11, 8}