1.
7/12 + 1/6 = 7/12 + 2/12 = 9/12 = 3/4 = 0,75
1 1/3 * 3/10 = 4/3 * 3/10 = 4/10 = 0,4
4/10 : 4/5 = 4/10 * 5/4 = 1/2 = 0,5
0,75 - 0,5 = 0,25
2.
1/3 : 2/3 = 1/3 * 3/2 = 1/2 = 0,5
0,5 - 3/8 = 0,5 - 0,375 = 0,125
0,125 * 2 = 0,25
0,25 + 3/4 = 0,25 + 0,75 = 1
3.
2/5 * 5/6 = 2/6 = 1/3
1/2 * 1 1/4 = 1/2 * 5/4 = 5/8 = 0,625
0,625 + 3/8 = 0,625 + 0,375 = 1
1 - 1/3 = 2/3
4.
5 : 17 3/5 = 5 * 5/88 = 25/88
25/88 + 5/8 = 25/88 + 55/88 = 80/88 = 10/11
10/11 * 11/10 = 1
1 - 2/9 = 7/9
5.
3/4 + 1/2 = 3/4 + 2/4 = 5/4 = 1 1/4 = 1,25
1,25 * 2 = 2,5
1/6 * 13 = 13/6 = 2 1/6
2,5 - 2 1/6 = 25/10 - 2 1/6 = 25/10 - 13/6 = 75/30 - 65/30 = 10/30 = 1/3
ответ 1,5
Решение задания прилагаю