(6405 #4 p. 321) Let R denote the region bounded by the parabola y = -x² + 6x - 5 and the line y = -x + 1. Let S denote the solid generated when the region R is revolved about the y-axis. Setup, but do not evaluate, an integral that would give the volume of S.

I need help and answer key for 14 and 15

I have this question on my homework and I don't see a pattern. I have to explain how the trick works.  "Think of a number. Add 17. Double the result. Subtract 4. Double the result. Add 20. Divide by 4. Subtract 20. Your answer will be your original number."

Enter a set of parentheses to make the equation =-8    6+3•2-4/2•5+8