а) 3 3/5 · 1/3 + 6 4/9 : 2 = 4 целых 19/45
1) 3 3/5 · 1/3 = 18/5 · 1/3 = (6·1)/(5·1) = 6/5 = 1 1/5
2) 6 4/9 : 2 = 58/9 · 1/2 = (29·1)/(9·1) = 29/9 = 3 2/9
3) 1 1/5 + 3 2/9 = 1 9/45 + 3 10/45 = 4 19/45
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б) 2/3 - 8/23 · (3/4 + 1 1/6) = 0
1) 3/4 + 1 1/6 = 9/12 + 1 2/12 = 1 11/12 = 23/12
2) 8/23 · 23/12 = (2·1)/(1·3) = 2/3
3) 2/3 - 2/3 = 0
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в) 2 5/6 - 1 1/5 · 1 1/9 + 1 5/7 : 1 1/7 = 3
1) 1 1/5 · 1 1/9 = 6/5 · 10/9 = (2·2)/(1·3) = 4/3 = 1 1/3
2) 1 5/7 : 1 1/7 = 12/7 : 8/7 = 12/7 · 7/8 = (3·1)/(1·2) = 3/2 = 1 1/2
3) 2 5/6 - 1 1/3 = 2 5/6 - 1 2/6 = 1 3/6 = 1 1/2
4) 1 1/2 + 1 1/2 = 2 2/2 = 3
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г) 5 2/9 : (3 - 1 1/9 · 2 2/5) + 4/5 = 16 целых 7/15
1) 1 1/9 · 2 2/5 = 10/9 · 12/5 = (2·4)/(3·1) = 8/3 = 2 2/3
2) 3 - 2 2/3 = 2 3/3 - 2 2/3 = 1/3
3) 5 2/9 : 1/3 = 47/9 · 3/1 = (47·1)/(3·1) = 47/3 = 15 2/3
4) 15 2/3 + 4/5 = 15 10/15 + 12/15 = 15 22/15 = 16 7/15
Решение на фоторафии.