Answer: A. 12.5
<u>Step-by-step explanation:</u>

Answer:
x = 25√2, y = 25
Step-by-step explanation:
x = 25(√2) = 25√2
y = 25
Answer:
70
Step-by-step explanation:
70 combinations of four books can be made from eight different books.
Answer:
C. 37.8 lb
Step-by-step explanation: