1) (х+5/12)-9/20=11/15; х+5/12=11/15+9/20; х+5/12=(11*4+9*3)/60;
х+5/12=(44+27)/60; х+5/12=71/60; х=71/60-5/12; х=71/60-25/60; х=46/60=23/30;
2) (х-11/30)-16/45=2/9; х-11/30=2/9+16/45; х-11/30=10/45+16/45;
х-11/30 = 26/45; х=26/45+11/30; х=52/90+33/90=85/90=17/18;
3) (х-7/15)+5/8=17/24; х-7/15=17/24-5/8; х-7/15=17/24-15/24; х-7/15=2/24=1/12;
х=1/12+7/15=5/60+28/60=33/60=11/20;
4) 4/5 - (х+1/60)=2/3;(х+1/60)=4/5-2/3=12/15-10/15=2/15; х=2/15-1/60=8/60-1/60=7/60
5) 4 3/4 - (х- 2 5/8)= 3 5/6; х-2 5/8= 4 3/4 - 3 5/6=1 9/12-10/12=21/12-10/12=11/12;
х=11/12+2 5/8=22/24+2 15/24 =2 + 37/24 = 3 13/24;
6) 9 9/28 - (4 5/21- х)= 6 2/7; 4 5/21- х=9 9/28-6 2/7=3 9/28-8/28=3 1/28;
х=4 5/21-3 1/28 = 1 5/21-1/28=26/21-1/28=(26*4-1*3)/84=(104-3)/84=101/84=1 17/84.