It's the same because you're trying to find net price (end price)
You're going to take in both scenarios 100%-15%= 85%
You're always going to be paying only 85% of the price.
Your welcome I’m glad to help out
Answer:
I cannot really see the q
I think the given series is

You can use the integral test because the summand is clearly positive and decreasing. Then

Substitute <em>u</em> = <em>x</em> ³ + 1 and d<em>u</em> = 3<em>x</em> ² d<em>x</em>, so the integral becomes

As <em>u</em> approaches infinity, we have ln(<em>u</em>) also approaching infinity (whereas 1/3 ln(9) is finite), so the integral and hence the sum diverges.