21b^3+51b^2+18b=0

Solution for 21b^3+51b^2+18b=0 equation:

Simplifying
21b3 + 51b2 + 18b = 0

Reorder the terms:
18b + 51b2 + 21b3 = 0

Solving
18b + 51b2 + 21b3 = 0

Solving for variable 'b'.

Factor out the Greatest Common Factor (GCF), '3b'.
3b(6 + 17b + 7b2) = 0

Factor a trinomial.
3b((2 + b)(3 + 7b)) = 0

Ignore the factor 3.
Subproblem 1
Set the factor 'b' equal to zero and attempt to solve:

Simplifying
b = 0

Solving
b = 0

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

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

Simplifying
2 + b = 0

Solving
2 + b = 0

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

Add '-2' to each side of the equation.
2 + -2 + b = 0 + -2

Combine like terms: 2 + -2 = 0
0 + b = 0 + -2
b = 0 + -2

Combine like terms: 0 + -2 = -2
b = -2

Simplifying
b = -2
Subproblem 3
Set the factor '(3 + 7b)' equal to zero and attempt to solve:

Simplifying
3 + 7b = 0

Solving
3 + 7b = 0

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

Add '-3' to each side of the equation.
3 + -3 + 7b = 0 + -3

Combine like terms: 3 + -3 = 0
0 + 7b = 0 + -3
7b = 0 + -3

Combine like terms: 0 + -3 = -3
7b = -3

Divide each side by '7'.
b = -0.4285714286

Simplifying
b = -0.4285714286
Solution
b = {0, -2, -0.4285714286}