I need help i don't understand this #2

Which expression is equivalent to7_/x^2 ÷ 5_/y^3? assume y# 0

Kayla made observations about the sellin price of a new brand of coffee that sold in the three different sized bags she recorded those observations in the following table 6 is $2.10 8 is $2.80 and 16 is to $5.60 use the relationship to predict the cost of a 20oz bag of coffee.

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