2b+3b+6=-21

Solution for 2b+3b+6=-21 equation:

Simplifying
2b + 3b + 6 = -21

Reorder the terms:
6 + 2b + 3b = -21

Combine like terms: 2b + 3b = 5b
6 + 5b = -21

Solving
6 + 5b = -21

Solving for variable 'b'.

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

Add '-6' to each side of the equation.
6 + -6 + 5b = -21 + -6

Combine like terms: 6 + -6 = 0
0 + 5b = -21 + -6
5b = -21 + -6

Combine like terms: -21 + -6 = -27
5b = -27

Divide each side by '5'.
b = -5.4

Simplifying
b = -5.4