3 8/11 + 9 3/11 = 12 11/11 = 13
х+6 1/9 = 13
x=13- 6 1/9
13-6 1/9 = 12 9/9 - 6 1/9=6 8/9
x= 6 8/9
х+ 6 1/9= 12 11/11
х+6 1/9=13
х=13-6 1/9
х=12 9/9 -6 1/9
х=6 8/9
3 8/11 + 9 3/11 = 12 11/11 = 13
х+6 1/9 = 13
x=13- 6 1/9
13-6 1/9 = 12 9/9 - 6 1/9=6 8/9
x= 6 8/9
х+ 6 1/9= 12 11/11
х+6 1/9=13
х=13-6 1/9
х=12 9/9 -6 1/9
х=6 8/9