(r+8)(r+5)=

Solution for (r+8)(r+5)= equation:

Simplifying
(r + 8)(r + 5) = 0

Reorder the terms:
(8 + r)(r + 5) = 0

Reorder the terms:
(8 + r)(5 + r) = 0

Multiply (8 + r) * (5 + r)
(8(5 + r) + r(5 + r)) = 0
((5 * 8 + r * 8) + r(5 + r)) = 0
((40 + 8r) + r(5 + r)) = 0
(40 + 8r + (5 * r + r * r)) = 0
(40 + 8r + (5r + r2)) = 0

Combine like terms: 8r + 5r = 13r
(40 + 13r + r2) = 0

Solving
40 + 13r + r2 = 0

Solving for variable 'r'.

Factor a trinomial.
(8 + r)(5 + r) = 0

Subproblem 1
Set the factor '(8 + r)' equal to zero and attempt to solve:

Simplifying
8 + r = 0

Solving
8 + r = 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 + r = 0 + -8

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

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

Simplifying
r = -8
Subproblem 2
Set the factor '(5 + r)' equal to zero and attempt to solve:

Simplifying
5 + r = 0

Solving
5 + r = 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 + r = 0 + -5

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

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

Simplifying
r = -5
Solution
r = {-8, -5}