-7x^2-21x+0=0

Solution for -7x^2-21x+0=0 equation:

Simplifying
-7x2 + -21x + 0 = 0

Reorder the terms:
0 + -21x + -7x2 = 0
Remove the zero:
-21x + -7x2 = 0

Solving
-21x + -7x2 = 0

Solving for variable 'x'.

Factor out the Greatest Common Factor (GCF), '-7x'.
-7x(3 + x) = 0

Ignore the factor -7.
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 '(3 + x)' equal to zero and attempt to solve:

Simplifying
3 + x = 0

Solving
3 + x = 0

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

Add '-3' to each side of the equation.
3 + -3 + x = 0 + -3

Combine like terms: 3 + -3 = 0
0 + x = 0 + -3
x = 0 + -3

Combine like terms: 0 + -3 = -3
x = -3

Simplifying
x = -3
Solution
x = {0, -3}