Answer:
r = 7
Step-by-step explanation:
These two angles are complementary which means they add to 90. That's how you get a workable equation.
5r + 5 + 8r - 6 = 90 Combine like terms
5r + 8r + 5 - 6 = 90
13r - 1 = 90 Add 1 to both sides.
13r = 90 + 1
13r = 91 Divide by 13
13r/13 = 91/13
r = 7
