(-1-r)(5-r)=

Solution for (-1-r)(5-r)= equation:

Simplifying
(-1 + -1r)(5 + -1r) = 0

Multiply (-1 + -1r) * (5 + -1r)
(-1(5 + -1r) + -1r * (5 + -1r)) = 0
((5 * -1 + -1r * -1) + -1r * (5 + -1r)) = 0
((-5 + 1r) + -1r * (5 + -1r)) = 0
(-5 + 1r + (5 * -1r + -1r * -1r)) = 0
(-5 + 1r + (-5r + 1r2)) = 0

Combine like terms: 1r + -5r = -4r
(-5 + -4r + 1r2) = 0

Solving
-5 + -4r + 1r2 = 0

Solving for variable 'r'.

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

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

Simplifying
-1 + -1r = 0

Solving
-1 + -1r = 0

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

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

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

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

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

Simplifying
r = -1
Subproblem 2
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
Solution
r = {-1, 5}