Evaluate each expression if r = 5, s = 2, t = 7, and u = 1. 1. s + 7 2. 9 – u 3. 3t + 1

4. 5r - 4 5. t – s 6. u + r

7. 11t – 7 8. 6 + 3u 9. 4r – 10s

10. 32 11. 22 – 18 12. 2 + 8

13. 2 14. 30 15. (3+)28

Evaluate each expression if a = 4.1, b = 5.7, and c = 0.3.

16. a + b – c 17. 10 – (a + b) 18. b – c + 2

19. MOON The expression 6 gives the weight of an object on the Moon in pounds with a weight of w pounds on Earth. What is the weight of a space suit on the Moon if the space suit weighs 178.2 pounds on Earth?