21b^2-15b=3b

Solution for 21b^2-15b=3b equation:

Simplifying
21b2 + -15b = 3b

Reorder the terms:
-15b + 21b2 = 3b

Solving
-15b + 21b2 = 3b

Solving for variable 'b'.

Reorder the terms:
-15b + -3b + 21b2 = 3b + -3b

Combine like terms: -15b + -3b = -18b
-18b + 21b2 = 3b + -3b

Combine like terms: 3b + -3b = 0
-18b + 21b2 = 0

Factor out the Greatest Common Factor (GCF), '3b'.
3b(-6 + 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 '(-6 + 7b)' equal to zero and attempt to solve:

Simplifying
-6 + 7b = 0

Solving
-6 + 7b = 0

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

Add '6' to each side of the equation.
-6 + 6 + 7b = 0 + 6

Combine like terms: -6 + 6 = 0
0 + 7b = 0 + 6
7b = 0 + 6

Combine like terms: 0 + 6 = 6
7b = 6

Divide each side by '7'.
b = 0.8571428571

Simplifying
b = 0.8571428571
Solution
b = {0, 0.8571428571}