75+20r+r^2=

Solution for 75+20r+r^2= equation:

Simplifying
75 + 20r + r2 = 0

Solving
75 + 20r + r2 = 0

Solving for variable 'r'.

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

Subproblem 1
Set the factor '(15 + r)' equal to zero and attempt to solve:

Simplifying
15 + r = 0

Solving
15 + r = 0

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

Add '-15' to each side of the equation.
15 + -15 + r = 0 + -15

Combine like terms: 15 + -15 = 0
0 + r = 0 + -15
r = 0 + -15

Combine like terms: 0 + -15 = -15
r = -15

Simplifying
r = -15
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 = {-15, -5}