280=(18-x)(x)+(20x)

Solution for 280=(18-x)(x)+(20x) equation:

Simplifying
280 = (18 + -1x)(x) + (20x)

Reorder the terms for easier multiplication:
280 = x(18 + -1x) + (20x)
280 = (18 * x + -1x * x) + (20x)
280 = (18x + -1x2) + (20x)

Reorder the terms:
280 = 18x + (20x) + -1x2

Combine like terms: 18x + (20x) = 38x
280 = 38x + -1x2

Solving
280 = 38x + -1x2

Solving for variable 'x'.

Reorder the terms:
280 + -38x + x2 = 38x + -38x + -1x2 + x2

Combine like terms: 38x + -38x = 0
280 + -38x + x2 = 0 + -1x2 + x2
280 + -38x + x2 = -1x2 + x2

Combine like terms: -1x2 + x2 = 0
280 + -38x + x2 = 0

Factor a trinomial.
(10 + -1x)(28 + -1x) = 0

Subproblem 1
Set the factor '(10 + -1x)' equal to zero and attempt to solve:

Simplifying
10 + -1x = 0

Solving
10 + -1x = 0

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

Add '-10' to each side of the equation.
10 + -10 + -1x = 0 + -10

Combine like terms: 10 + -10 = 0
0 + -1x = 0 + -10
-1x = 0 + -10

Combine like terms: 0 + -10 = -10
-1x = -10

Divide each side by '-1'.
x = 10

Simplifying
x = 10
Subproblem 2
Set the factor '(28 + -1x)' equal to zero and attempt to solve:

Simplifying
28 + -1x = 0

Solving
28 + -1x = 0

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

Add '-28' to each side of the equation.
28 + -28 + -1x = 0 + -28

Combine like terms: 28 + -28 = 0
0 + -1x = 0 + -28
-1x = 0 + -28

Combine like terms: 0 + -28 = -28
-1x = -28

Divide each side by '-1'.
x = 28

Simplifying
x = 28
Solution
x = {10, 28}