4(b-3.9)=7.8(b+1)

Solution for 4(b-3.9)=7.8(b+1) equation:

Simplifying
4(b + -3.9) = 7.8(b + 1)

Reorder the terms:
4(-3.9 + b) = 7.8(b + 1)
(-3.9 * 4 + b * 4) = 7.8(b + 1)
(-15.6 + 4b) = 7.8(b + 1)

Reorder the terms:
-15.6 + 4b = 7.8(1 + b)
-15.6 + 4b = (1 * 7.8 + b * 7.8)
-15.6 + 4b = (7.8 + 7.8b)

Solving
-15.6 + 4b = 7.8 + 7.8b

Solving for variable 'b'.

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

Add '-7.8b' to each side of the equation.
-15.6 + 4b + -7.8b = 7.8 + 7.8b + -7.8b

Combine like terms: 4b + -7.8b = -3.8b
-15.6 + -3.8b = 7.8 + 7.8b + -7.8b

Combine like terms: 7.8b + -7.8b = 0.0
-15.6 + -3.8b = 7.8 + 0.0
-15.6 + -3.8b = 7.8

Add '15.6' to each side of the equation.
-15.6 + 15.6 + -3.8b = 7.8 + 15.6

Combine like terms: -15.6 + 15.6 = 0.0
0.0 + -3.8b = 7.8 + 15.6
-3.8b = 7.8 + 15.6

Combine like terms: 7.8 + 15.6 = 23.4
-3.8b = 23.4

Divide each side by '-3.8'.
b = -6.157894737

Simplifying
b = -6.157894737