Sn = n/2 (a1+an)
= 8/2 (3-38)
= 4 (-35)
= -140
Hi, seems like the answer is f(x) = x - 4
Edit: this was my original answer, but I was apparently completely out of my mind when I wrote it. The correct answer is f(x) = -4x + 50, as I stated below. I'm very sorry for any trouble I caused
I say it's "You pay fewer up-front costs".
