84n^2+21n=0

Solution for 84n^2+21n=0 equation:

Simplifying
84n2 + 21n = 0

Reorder the terms:
21n + 84n2 = 0

Solving
21n + 84n2 = 0

Solving for variable 'n'.

Factor out the Greatest Common Factor (GCF), '21n'.
21n(1 + 4n) = 0

Ignore the factor 21.
Subproblem 1
Set the factor 'n' equal to zero and attempt to solve:

Simplifying
n = 0

Solving
n = 0

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

Simplifying
n = 0
Subproblem 2
Set the factor '(1 + 4n)' equal to zero and attempt to solve:

Simplifying
1 + 4n = 0

Solving
1 + 4n = 0

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

Add '-1' to each side of the equation.
1 + -1 + 4n = 0 + -1

Combine like terms: 1 + -1 = 0
0 + 4n = 0 + -1
4n = 0 + -1

Combine like terms: 0 + -1 = -1
4n = -1

Divide each side by '4'.
n = -0.25

Simplifying
n = -0.25
Solution
n = {0, -0.25}