3=-7r+8r

Solution for 3=-7r+8r equation:

Simplifying
3 = -7r + 8r

Combine like terms: -7r + 8r = 1r
3 = 1r

Solving
3 = 1r

Solving for variable 'r'.

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

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

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

Add '-3' to each side of the equation.
3 + -3 + -1r = 0 + -3

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

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

Divide each side by '-1'.
r = 3

Simplifying
r = 3