(2.1b-1.2)=4(0.7b+0.85)

Solution for (2.1b-1.2)=4(0.7b+0.85) equation:

Simplifying
(2.1b + -1.2) = 4(0.7b + 0.85)

Reorder the terms:
(-1.2 + 2.1b) = 4(0.7b + 0.85)

Remove parenthesis around (-1.2 + 2.1b)
-1.2 + 2.1b = 4(0.7b + 0.85)

Reorder the terms:
-1.2 + 2.1b = 4(0.85 + 0.7b)
-1.2 + 2.1b = (0.85 * 4 + 0.7b * 4)
-1.2 + 2.1b = (3.4 + 2.8b)

Solving
-1.2 + 2.1b = 3.4 + 2.8b

Solving for variable 'b'.

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

Add '-2.8b' to each side of the equation.
-1.2 + 2.1b + -2.8b = 3.4 + 2.8b + -2.8b

Combine like terms: 2.1b + -2.8b = -0.7b
-1.2 + -0.7b = 3.4 + 2.8b + -2.8b

Combine like terms: 2.8b + -2.8b = 0.0
-1.2 + -0.7b = 3.4 + 0.0
-1.2 + -0.7b = 3.4

Add '1.2' to each side of the equation.
-1.2 + 1.2 + -0.7b = 3.4 + 1.2

Combine like terms: -1.2 + 1.2 = 0.0
0.0 + -0.7b = 3.4 + 1.2
-0.7b = 3.4 + 1.2

Combine like terms: 3.4 + 1.2 = 4.6
-0.7b = 4.6

Divide each side by '-0.7'.
b = -6.571428571

Simplifying
b = -6.571428571