105=3b+4b

Solution for 105=3b+4b equation:

Simplifying
105 = 3b + 4b

Combine like terms: 3b + 4b = 7b
105 = 7b

Solving
105 = 7b

Solving for variable 'b'.

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

Add '-7b' to each side of the equation.
105 + -7b = 7b + -7b

Combine like terms: 7b + -7b = 0
105 + -7b = 0

Add '-105' to each side of the equation.
105 + -105 + -7b = 0 + -105

Combine like terms: 105 + -105 = 0
0 + -7b = 0 + -105
-7b = 0 + -105

Combine like terms: 0 + -105 = -105
-7b = -105

Divide each side by '-7'.
b = 15

Simplifying
b = 15