Đáp án:
Giải thích các bước giải:
2/3 : 5/4 : 7/6 2/3 : 7/6 : 5/4
= 8/15 : 7/6 = 12/21 : 5/4
= 48/ 105 = 48/105
2/3 : 4/3 : 5/4 2/3 : 5/4 : 4/3
= 1/2 : 5/4 = 8/15 : 4/3
= 4/10 = 4/10
2: 2/3 : 3/4 2: 3/4 : 2/3
= 2/1 : 2/3: 3/4 = 2/1 : 3/4 : 2/3
= 3/1: 3/4 = 8/3 : 2/3
= 4 = 4