Rst is a right triangle rs=12 rt=20 st=15 what is sin r

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.

George writes the mixed number as sum and uses the distributive property 1/2.-2/5=1/2-2+2/5=1/2