4,5 · 2/3 - 1 5/7 : 1,2 + 2 1/5 · 3 1/8 = 8 25/56
1) 4,5 · 2/3 = 4,5 · 2 : 3 = 9 : 3 = 3
2) 1 5/7 : 1,2 = 12/7 : 12/10 = 12/7 · 10/12 = 10/7 = 1 3/7
3) 2 1/5 · 3 1/8 = 11/5 · 25/8 = (11·5)/(1·8) = 55/8 = 6 7/8
4) 3 - 1 3/7 = 2 7/7 - 1 3/7 = 1 4/7
5) 1 4/7 + 6 7/8 = 1 32/56 + 6 49/56 = 7 81/56 = 8 25/56
ответ: 8 целых 25/56.
4,5 · 2/3 - 1 5/7 : 1,2 + 2 1/5 · 3 1/8 = 8 25/56
1) 4,5 · 2/3 = 4,5 · 2 : 3 = 9 : 3 = 3
2) 1 5/7 : 1,2 = 12/7 : 12/10 = 12/7 · 10/12 = 10/7 = 1 3/7
3) 2 1/5 · 3 1/8 = 11/5 · 25/8 = (11·5)/(1·8) = 55/8 = 6 7/8
4) 3 - 1 3/7 = 2 7/7 - 1 3/7 = 1 4/7
5) 1 4/7 + 6 7/8 = 1 32/56 + 6 49/56 = 7 81/56 = 8 25/56
ответ: 8 целых 25/56.