1) х + 2/11 = 5
х = 5 - 2/11
х = (55-2)/11
х=53/11
х= 4 9/11
2) 26 5/8+а=30
а=30- 26 5/8
а= 29 8/8 - 26 5/8
а= 3 3/8
3) n-65/66=2/9
n= 65/66 = 2/9
n= 44/198 + 195/198
n= 239/198
n= 1 41/198
4) 11 1/4-x=3 7/10
-х = 3 7/10 - 11 1/4
-х = 3 14/20 - 10 25/20
-х = -7 11/20
х = 7 11/20