1) 6/2x+1=8/7 2) 2+3x/4=5/9 /-дробь !

1)
6/2х + 1 = 8/7
3х = 8/7 - 7/7
3х = 1/7 | : 3
х = 1/7 : 3/1
х = 1/7 * 1/3
х = 1/21

2)
2 + 3/4х = 5/9
3/4х = 5/9 - 2
3/4х = 5/9 - 18/9
3/4х = -13/9 | : 3/4
х = -13/9 : 3/4
х = 13/9 * 4/3
х = 52/27(выделить целую часть)