Answer:
r = -3
Explanation:
Simplifying
5r + 15 = 0
Reorder the terms:
15 + 5r = 0
Solving
15 + 5r = 0
Solving for variable 'r'.
Move all terms containing r to the left, all other terms to the right.
Add '-15' to each side of the equation.
15 + -15 + 5r = 0 + -15
Combine like terms: 15 + -15 = 0
0 + 5r = 0 + -15
5r = 0 + -15
Combine like terms: 0 + -15 = -15
5r = -15
Divide each side by '5'.
r = -3
Simplifying
r = -3