x+4/7=3/4 x-3/4=2/5 x x 2/3=3/4x1/2
x=3/4-4/7 x=2/5+3/4 x x2/3=3/8
x=21/28-16/28 x=8/20+15/20 x=3/8:2/3
x=5/28 x=23/20 x=9/16
1. Đề:...........
<=> x = 3/4 - 4/7
<=> x = 5/28
Vậy x = 5/28
2. Đề:............
<=> x = 2/5 + 3/4
<=> x = 23/20
Vậy x = 23/20
3. Đề:..........
<=> x. 2/3 = 3/8
<=> x = 3/8. 3/2
<=> x = 9/16
Vậy x = 9/16