21X+X^2=

Solution for 21X+X^2= equation:

Simplifying
21X + X2 = 0

Solving
21X + X2 = 0

Solving for variable 'X'.

Factor out the Greatest Common Factor (GCF), 'X'.
X(21 + X) = 0

Subproblem 1
Set the factor 'X' equal to zero and attempt to solve:

Simplifying
X = 0

Solving
X = 0

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

Simplifying
X = 0
Subproblem 2
Set the factor '(21 + X)' equal to zero and attempt to solve:

Simplifying
21 + X = 0

Solving
21 + X = 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 + X = 0 + -21

Combine like terms: 21 + -21 = 0
0 + X = 0 + -21
X = 0 + -21

Combine like terms: 0 + -21 = -21
X = -21

Simplifying
X = -21
Solution
X = {0, -21}