(r+7)(r+8)=

Solution for (r+7)(r+8)= equation:

Simplifying
(r + 7)(r + 8) = 0

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

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

Multiply (7 + r) * (8 + r)
(7(8 + r) + r(8 + r)) = 0
((8 * 7 + r * 7) + r(8 + r)) = 0
((56 + 7r) + r(8 + r)) = 0
(56 + 7r + (8 * r + r * r)) = 0
(56 + 7r + (8r + r2)) = 0

Combine like terms: 7r + 8r = 15r
(56 + 15r + r2) = 0

Solving
56 + 15r + r2 = 0

Solving for variable 'r'.

Factor a trinomial.
(8 + r)(7 + 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 '(7 + r)' equal to zero and attempt to solve:

Simplifying
7 + r = 0

Solving
7 + r = 0

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

Add '-7' to each side of the equation.
7 + -7 + r = 0 + -7

Combine like terms: 7 + -7 = 0
0 + r = 0 + -7
r = 0 + -7

Combine like terms: 0 + -7 = -7
r = -7

Simplifying
r = -7
Solution
r = {-8, -7}