1) 7 < 2х + 3 < 11
7-3 < 2x < 11-3
4 < 2x < 8
2 < x < 4
2) -3 < 1+2х < 7
-3-1 < 2x < 7-1
-4 < 2x < 6
-2 < x < 3
3) опечатка в записи
4) -7 < 2х+1/2 < 2
-7-1/2 < 2x < 2-1/2
-6 1/2 < 2x < 1 1/2
-3 1/4 < x < 3/4
1) 7 < 2х + 3 < 11
7-3 < 2x < 11-3
4 < 2x < 8
2 < x < 4
2) -3 < 1+2х < 7
-3-1 < 2x < 7-1
-4 < 2x < 6
-2 < x < 3
3) опечатка в записи
4) -7 < 2х+1/2 < 2
-7-1/2 < 2x < 2-1/2
-6 1/2 < 2x < 1 1/2
-3 1/4 < x < 3/4