-(3-r)=7r-3+2r

Solution for -(3-r)=7r-3+2r equation:

Simplifying
-1(3 + -1r) = 7r + -3 + 2r
(3 * -1 + -1r * -1) = 7r + -3 + 2r
(-3 + 1r) = 7r + -3 + 2r

Reorder the terms:
-3 + 1r = -3 + 7r + 2r

Combine like terms: 7r + 2r = 9r
-3 + 1r = -3 + 9r

Add '3' to each side of the equation.
-3 + 3 + 1r = -3 + 3 + 9r

Combine like terms: -3 + 3 = 0
0 + 1r = -3 + 3 + 9r
1r = -3 + 3 + 9r

Combine like terms: -3 + 3 = 0
1r = 0 + 9r
1r = 9r

Solving
1r = 9r

Solving for variable 'r'.

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

Add '-9r' to each side of the equation.
1r + -9r = 9r + -9r

Combine like terms: 1r + -9r = -8r
-8r = 9r + -9r

Combine like terms: 9r + -9r = 0
-8r = 0

Divide each side by '-8'.
r = 0

Simplifying
r = 0