What is the sum of (2a - 3b) and (5b - a)

What is the volume of the cone to the nearest cubic millimeter? (use π  = 3.14) a) 46 mm3 b) 128 mm3 c) 183 mm3 d) 275 mm3 diameter = 5 mm height = 7 mm how do you do this problem step by step?

Which geometric principle is used to justify the construction below?

Plzzz answer both questions and i will give you 100 points