#1 is confusing and i messed up a couple times, needed

Acyclist bike x distance at 10 miles per hour .and returns over the same path at 8 miles per hour.what is the cyclist average rate for the round trip in miles per hour ?

What is the value of n in the equation -1/2(2n+4)+6=-9+4(2n+1)

Dawn is selling her mp3 player for 3 4 of the original price. the original price for the mp3 player was $40. how much is she selling her mp3 player for?