(x+1)(x-5)=40

Solution for (x+1)(x-5)=40 equation:

Simplifying
(x + 1)(x + -5) = 40

Reorder the terms:
(1 + x)(x + -5) = 40

Reorder the terms:
(1 + x)(-5 + x) = 40

Multiply (1 + x) * (-5 + x)
(1(-5 + x) + x(-5 + x)) = 40
((-5 * 1 + x * 1) + x(-5 + x)) = 40
((-5 + 1x) + x(-5 + x)) = 40
(-5 + 1x + (-5 * x + x * x)) = 40
(-5 + 1x + (-5x + x2)) = 40

Combine like terms: 1x + -5x = -4x
(-5 + -4x + x2) = 40

Solving
-5 + -4x + x2 = 40

Solving for variable 'x'.

Reorder the terms:
-5 + -40 + -4x + x2 = 40 + -40

Combine like terms: -5 + -40 = -45
-45 + -4x + x2 = 40 + -40

Combine like terms: 40 + -40 = 0
-45 + -4x + x2 = 0

Factor a trinomial.
(-5 + -1x)(9 + -1x) = 0

Subproblem 1
Set the factor '(-5 + -1x)' equal to zero and attempt to solve:

Simplifying
-5 + -1x = 0

Solving
-5 + -1x = 0

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

Add '5' to each side of the equation.
-5 + 5 + -1x = 0 + 5

Combine like terms: -5 + 5 = 0
0 + -1x = 0 + 5
-1x = 0 + 5

Combine like terms: 0 + 5 = 5
-1x = 5

Divide each side by '-1'.
x = -5

Simplifying
x = -5
Subproblem 2
Set the factor '(9 + -1x)' equal to zero and attempt to solve:

Simplifying
9 + -1x = 0

Solving
9 + -1x = 0

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

Add '-9' to each side of the equation.
9 + -9 + -1x = 0 + -9

Combine like terms: 9 + -9 = 0
0 + -1x = 0 + -9
-1x = 0 + -9

Combine like terms: 0 + -9 = -9
-1x = -9

Divide each side by '-1'.
x = 9

Simplifying
x = 9
Solution
x = {-5, 9}