(x)(x+4)=357

Solution for (x)(x+4)=357 equation:

Simplifying
(x)(x + 4) = 357

Reorder the terms:
x(4 + x) = 357
(4 * x + x * x) = 357
(4x + x2) = 357

Solving
4x + x2 = 357

Solving for variable 'x'.

Reorder the terms:
-357 + 4x + x2 = 357 + -357

Combine like terms: 357 + -357 = 0
-357 + 4x + x2 = 0

Factor a trinomial.
(-21 + -1x)(17 + -1x) = 0

Subproblem 1
Set the factor '(-21 + -1x)' equal to zero and attempt to solve:

Simplifying
-21 + -1x = 0

Solving
-21 + -1x = 0

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

Add '21' to each side of the equation.
-21 + 21 + -1x = 0 + 21

Combine like terms: -21 + 21 = 0
0 + -1x = 0 + 21
-1x = 0 + 21

Combine like terms: 0 + 21 = 21
-1x = 21

Divide each side by '-1'.
x = -21

Simplifying
x = -21
Subproblem 2
Set the factor '(17 + -1x)' equal to zero and attempt to solve:

Simplifying
17 + -1x = 0

Solving
17 + -1x = 0

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

Add '-17' to each side of the equation.
17 + -17 + -1x = 0 + -17

Combine like terms: 17 + -17 = 0
0 + -1x = 0 + -17
-1x = 0 + -17

Combine like terms: 0 + -17 = -17
-1x = -17

Divide each side by '-1'.
x = 17

Simplifying
x = 17
Solution
x = {-21, 17}