I suppose you mean

Differentiate one term at a time.
Rewrite the first term as

Then the product rule says

Then with the power and chain rules,

Simplify this a bit by factoring out
:

For the second term, recall that

Then by the chain rule,

So we have

and we can simplify this by factoring out
to end up with

I think you can do this way:
Volume = B*h where B is the area of the base.
B= 4 * 10 = 40
V= 40 * 15
V= 600 cm^3
2-3k because the difference between something means it is subtraction and the product of 3 and k would just be 3k since you don't know what k is.