А)
1) 3/4 +1/6 = 9/12 + 2/12 =11/12
2) 11/12 * 3 = 11/4
3) 5/6 - 1/2 = 5/6 - 3/6 = 2/6 = 1/3
4) 1/3 : 2/9 = 1/3 * 9/2 = 3/2
5) 11/4 +3/2 = 11/4 + 6/4=17/4 =4целых 1/4
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б)
1) 1 1/5 + 2 3/10 = 1 2/10 + 2 3/10 = 3 5/10 =3 1/2
2) 3 1/2 : 1/2 =7/2 * 2/1 = 7
3) 6 3/4 - 2 2/3 = 6 9/12 - 2 8/12 = 4 1/12
4) 4 1/12 : 1 1/6 = 49/12 * 6/7 = 7/2 = 3 1/2
5) 7 + 3 1/2 = 10целых 1/2