15.6+5.2+6.5+b=42.5

Solution for 15.6+5.2+6.5+b=42.5 equation:

Simplifying
15.6 + 5.2 + 6.5 + b = 42.5

Combine like terms: 15.6 + 5.2 = 20.8
20.8 + 6.5 + b = 42.5

Combine like terms: 20.8 + 6.5 = 27.3
27.3 + b = 42.5

Solving
27.3 + b = 42.5

Solving for variable 'b'.

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

Add '-27.3' to each side of the equation.
27.3 + -27.3 + b = 42.5 + -27.3

Combine like terms: 27.3 + -27.3 = 0.0
0.0 + b = 42.5 + -27.3
b = 42.5 + -27.3

Combine like terms: 42.5 + -27.3 = 15.2
b = 15.2

Simplifying
b = 15.2