15=0.3*b

Solution for 15=0.3*b equation:

Simplifying
15 = 0.3b

Solving
15 = 0.3b

Solving for variable 'b'.

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

Add '-0.3b' to each side of the equation.
15 + -0.3b = 0.3b + -0.3b

Combine like terms: 0.3b + -0.3b = 0.0
15 + -0.3b = 0.0

Add '-15' to each side of the equation.
15 + -15 + -0.3b = 0.0 + -15

Combine like terms: 15 + -15 = 0
0 + -0.3b = 0.0 + -15
-0.3b = 0.0 + -15

Combine like terms: 0.0 + -15 = -15
-0.3b = -15

Divide each side by '-0.3'.
b = 50

Simplifying
b = 50