3x^2 - 8(y+2) divided by 2y for x=8 and y= -2

Idon’t understand this.. will someone ? will mark brainliest along with 20 points.

Turner's mom measured his room to see how long the wallpaper border needed to be. if two walls are 15 feet long and two walls are 12 feet long, how long should the strip of border be cut?

If x is 6, then 7x= a. 13 b. 42 c. 42x d. 76