Answer:
m=-3
Step-by-step explanation:
10=7-m
m=7-10=-3
(21-8)-6=7
and that's it
Surface area = 70π cm²
Surface area = πr² + πrl
Surface area = (π × 5 × 5) + (π × 5 × 9)
Surface area = (25π) + (45π)