42+12r=-3(1-6r)+3r

Solution for 42+12r=-3(1-6r)+3r equation:

Simplifying
42 + 12r = -3(1 + -6r) + 3r
42 + 12r = (1 * -3 + -6r * -3) + 3r
42 + 12r = (-3 + 18r) + 3r

Combine like terms: 18r + 3r = 21r
42 + 12r = -3 + 21r

Solving
42 + 12r = -3 + 21r

Solving for variable 'r'.

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

Add '-21r' to each side of the equation.
42 + 12r + -21r = -3 + 21r + -21r

Combine like terms: 12r + -21r = -9r
42 + -9r = -3 + 21r + -21r

Combine like terms: 21r + -21r = 0
42 + -9r = -3 + 0
42 + -9r = -3

Add '-42' to each side of the equation.
42 + -42 + -9r = -3 + -42

Combine like terms: 42 + -42 = 0
0 + -9r = -3 + -42
-9r = -3 + -42

Combine like terms: -3 + -42 = -45
-9r = -45

Divide each side by '-9'.
r = 5

Simplifying
r = 5