Answer:
see explanation
Step-by-step explanation:
2 × 
= 2 × 10 × 10 × 10 × 10
= 2 × 100 × 100
= 200 × 100
= 20000
And

= 2 × 2 × 2 × 2
= 4 × 4
= 16
Answer:
V≈7853.98
Step-by-step explanation:
V=πr2h
r=10
h=25
Solution
V=πr2h=π·102·25≈7853.98163
If my calculations are correct the answer is cut your answer in half
7b/12=4.2
7b=50.4
b=7.2
hope this helps