Can someone check over my answers to see if they're correct please?

The area of a rectangle is 54x^9y^8 square yards.if the length of the rectangle is 6x^3y^4 yards,which expression represents the width of the rectangle in yards

Frank owns a $141,000 home, for which he has a 30-year mortgage in the amount of $700 a month. once he has paid off mortgage, how much will he have paid in investment? a. $111,000 b. $109,000 c. $120,000 d. $141,000

Delbert keeps track of total of the total number of points he earns on homework assignments, each of which is worth 60 points. at the end of the semester he has 810 points. write an equation for delbert’s average homework score a in terms of the number of assignments n.