The answer is a. here’s a picture that hopefully helps explain the reasoning/work
Answer:

Step-by-step explanation:
• 
Let's use FOIL (first, outer, inner, last) to solve this. We'll multiply the terms by one another in that fashion.

Rearrange in decreasing exponents.

No it’s not the square root of 32 is 5.65685424949
350(1+0.75)t (add the numbers)
350*1.75t (Calculate the product)
612.5 t