(40 61/80-7 17/20)+25 3/40

1. 40 61\80 - 7 17\20 = 3261\80 - 157\20 = 3261\80 - 628\80 = 2633\80 2 2633\80 + 25 3\40 = 2633\80 + 1000\40 = 2633\80 + 2000\80 = 4633\80 = 57 73\80