Пошаговое объяснение:
13/25 + 2/25+3/25 = 18/25 = 72/100 = 0,72
19/34 - 6/34 + 3/34= 16/34 = 8/17
7/90 + 55/90 + 5/90 = 67/90
23/40+5/40+1/40 = 29/40 = 2,9/4 = 0,725
63/80 + 15/80 - 9/80 = 69/80 = 0,8625
(20/145 + 18/145)+ 29/145 = 38/145 + 29/145 = 67/145
