7560 in the ratio 4:5

Can someone check if i did this right since i really want to make sure it’s correct. if you do you so much

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.

Find the difference in area between the circle and the triangle. click on the answer until the correct answer is showing.possible answers: a = 4 pi - 8a = 9 pi - 9/2 √3a = 16/3 pia = 16a = 27 pi