-5n(n+1)=-20-5n

Solution for -5n(n+1)=-20-5n equation:

Simplifying
-5n(n + 1) = -20 + -5n

Reorder the terms:
-5n(1 + n) = -20 + -5n
(1 * -5n + n * -5n) = -20 + -5n
(-5n + -5n2) = -20 + -5n

Add '5n' to each side of the equation.
-5n + 5n + -5n2 = -20 + -5n + 5n

Combine like terms: -5n + 5n = 0
0 + -5n2 = -20 + -5n + 5n
-5n2 = -20 + -5n + 5n

Combine like terms: -5n + 5n = 0
-5n2 = -20 + 0
-5n2 = -20

Solving
-5n2 = -20

Solving for variable 'n'.

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

Divide each side by '-5'.
n2 = 4

Simplifying
n2 = 4

Take the square root of each side:
n = {-2, 2}