Вычислите 3\4•1 1\7:2/15 12 1/4:7 1/2=?

3/4 · 1 1/7 : 2/15 = 6 3/7

1) 3/4 · 1 1/7 = 3/4 · 8/7 = (3·2)/(1·7) = 6/7;

2) 6/7 : 2/15 = 6/7 · 15/2 = (3·15)/(7·1) = 45/7 = 6 3/7.

ответ: 6 целых 3/7.

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12 1/4 : 7 1/2 = 49/4 : 15/2 = 49/4 · 2/15 = (49·1)/(2·15) = 49/30 = 1 19/30

ответ: 1 целая 19/30.