105=-5r

Solution for 105=-5r equation:

Simplifying
105 = -5r

Solving
105 = -5r

Solving for variable 'r'.

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

Add '5r' to each side of the equation.
105 + 5r = -5r + 5r

Combine like terms: -5r + 5r = 0
105 + 5r = 0

Add '-105' to each side of the equation.
105 + -105 + 5r = 0 + -105

Combine like terms: 105 + -105 = 0
0 + 5r = 0 + -105
5r = 0 + -105

Combine like terms: 0 + -105 = -105
5r = -105

Divide each side by '5'.
r = -21

Simplifying
r = -21