1.
4 8/9+6 7/8:(5 11/12-3 5/6)*1 2/3=10 7/18
1)5 11/12-3 5/6=5 11/12-3 10/12=2 1/12
2)6 7/8:2 1/12=55/8:25/12=55/8*12/25=33/10
3)33/10*1 2/3=33/10*5/3=11/2
4)4 8/9+11/2=44/9+11/2=88/18+99/18=187/18=10 7/18
2.
(х+1,3)/(х-6,4)=(11,6-2,65)/(0,35+0,9)
(х+1,3)/(х-6,4)=8,95/1,25
8,95*(х-6,4)=1,25*(х+1,3)
8,95х-57,28=1,25х+1,625
8,95х-1,25х=57,28+1,625
7,7х=58,905
х=58,905:7,7
х=7,65