Write an equivalent expression to 9y -1/2(4y+20)

Geometry paper. i don't know how to do the rest. questions 5. 8. 9. and 10.

Runner ran 1 4/5 miles on monday and 6 3/10 on tuesday. how many times her monday’s distance was her tuesdays distance

Three numbers x, y, and z are in the ratio 2: 7: 8. if 12 is subtracted from y, then three numbers form a geometric sequence (in the order x, y–12, z). find x, y, and z. there are 2 sets.