Answer: D, 40 and 50
Steps:
1. Since complementary angles equal 90 degrees, 4r + 5r = 90
2. 4r + 5r is 9r
3. This makes the equation, 9r=90
4. Divide both sides by 9, and then you get r=10
5. Substitute r=10 into 4r and 5r
6. This should make 4(10) and 5(10)
7. Multiply and then get 40 and 50