Вычислите а) 2/3+0,15-17/60= б)9/14-(19/35+2/21)= надо пож

2/3 + 0,15 - 17/60 = 40/60 - 17/60 + 15/100 = 23/60 + 3/20 = 23/60 + 9/60 = 32/60 = 8/15
ответ 8/15
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9/14 - ( 19/35 + 2/21 ) = 9/14 - 2/21 - 19/35 = 27/42 - 4/42 - 19/35 = 23/42 - 19/35 = 115/210 - 114/210 = 1/210
ответ 1/210