The 20% statement is useless
80% of $295 is what?
80%×295=??
.80 × 295 = $236.00 in savings
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

Answer:
-6/5
Step-by-step explanation:
I hope it helps, bye