X^2+20X+100=400

Solution for X^2+20X+100=400 equation:

Simplifying
X2 + 20X + 100 = 400

Reorder the terms:
100 + 20X + X2 = 400

Solving
100 + 20X + X2 = 400

Solving for variable 'X'.

Reorder the terms:
100 + -400 + 20X + X2 = 400 + -400

Combine like terms: 100 + -400 = -300
-300 + 20X + X2 = 400 + -400

Combine like terms: 400 + -400 = 0
-300 + 20X + X2 = 0

Factor a trinomial.
(-30 + -1X)(10 + -1X) = 0

Subproblem 1
Set the factor '(-30 + -1X)' equal to zero and attempt to solve:

Simplifying
-30 + -1X = 0

Solving
-30 + -1X = 0

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

Add '30' to each side of the equation.
-30 + 30 + -1X = 0 + 30

Combine like terms: -30 + 30 = 0
0 + -1X = 0 + 30
-1X = 0 + 30

Combine like terms: 0 + 30 = 30
-1X = 30

Divide each side by '-1'.
X = -30

Simplifying
X = -30
Subproblem 2
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
Solution
X = {-30, 10}