300=(x+5)(x)

Solution for 300=(x+5)(x) equation:

Simplifying
300 = (x + 5)(x)

Reorder the terms:
300 = (5 + x)(x)

Reorder the terms for easier multiplication:
300 = x(5 + x)
300 = (5 * x + x * x)
300 = (5x + x2)

Solving
300 = 5x + x2

Solving for variable 'x'.

Reorder the terms:
300 + -5x + -1x2 = 5x + -5x + x2 + -1x2

Combine like terms: 5x + -5x = 0
300 + -5x + -1x2 = 0 + x2 + -1x2
300 + -5x + -1x2 = x2 + -1x2

Combine like terms: x2 + -1x2 = 0
300 + -5x + -1x2 = 0

Factor a trinomial.
(15 + -1x)(20 + x) = 0

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

Simplifying
15 + -1x = 0

Solving
15 + -1x = 0

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

Add '-15' to each side of the equation.
15 + -15 + -1x = 0 + -15

Combine like terms: 15 + -15 = 0
0 + -1x = 0 + -15
-1x = 0 + -15

Combine like terms: 0 + -15 = -15
-1x = -15

Divide each side by '-1'.
x = 15

Simplifying
x = 15
Subproblem 2
Set the factor '(20 + x)' equal to zero and attempt to solve:

Simplifying
20 + x = 0

Solving
20 + x = 0

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

Add '-20' to each side of the equation.
20 + -20 + x = 0 + -20

Combine like terms: 20 + -20 = 0
0 + x = 0 + -20
x = 0 + -20

Combine like terms: 0 + -20 = -20
x = -20

Simplifying
x = -20
Solution
x = {15, -20}