42=4r-2(1-2r)

Solution for 42=4r-2(1-2r) equation:

Simplifying
42 = 4r + -2(1 + -2r)
42 = 4r + (1 * -2 + -2r * -2)
42 = 4r + (-2 + 4r)

Reorder the terms:
42 = -2 + 4r + 4r

Combine like terms: 4r + 4r = 8r
42 = -2 + 8r

Solving
42 = -2 + 8r

Solving for variable 'r'.

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

Add '-8r' to each side of the equation.
42 + -8r = -2 + 8r + -8r

Combine like terms: 8r + -8r = 0
42 + -8r = -2 + 0
42 + -8r = -2

Add '-42' to each side of the equation.
42 + -42 + -8r = -2 + -42

Combine like terms: 42 + -42 = 0
0 + -8r = -2 + -42
-8r = -2 + -42

Combine like terms: -2 + -42 = -44
-8r = -44

Divide each side by '-8'.
r = 5.5

Simplifying
r = 5.5