1Целая 3/5+(51÷42-1/4)*7/9=
1) 51 : 42 = 1 9/42 1) 1 9/42 - 1/4 = 1 18/84 - 21/84 = 102/84 - 21/84 = 81/84 3) 81/84 • 7/9 = 9/12 = 3/4 4) 1 3/5 + 3/4 = 1 12/20 + 15/20 = 1 27/20 = 2 7/20 Ответ 2 7/20