63=15b+6b

Solution for 63=15b+6b equation:

Simplifying
63 = 15b + 6b

Combine like terms: 15b + 6b = 21b
63 = 21b

Solving
63 = 21b

Solving for variable 'b'.

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

Add '-21b' to each side of the equation.
63 + -21b = 21b + -21b

Combine like terms: 21b + -21b = 0
63 + -21b = 0

Add '-63' to each side of the equation.
63 + -63 + -21b = 0 + -63

Combine like terms: 63 + -63 = 0
0 + -21b = 0 + -63
-21b = 0 + -63

Combine like terms: 0 + -63 = -63
-21b = -63

Divide each side by '-21'.
b = 3

Simplifying
b = 3