Answer:
5a^2 +2a
Step-by-step explanation:
Like terms are ones with the same exponent of x. They can be combined.
3a^2 +2a +2a^2
= (3a^2 +2a^2) +2a
= (3+2)a^2 +2a
= 5a^2 +2a
Assuming it is a right rectangular prism, the volume is 126 sq. in.
V = area of base * height = 18 * 7 = 126
