А)2/3+х=1
х=1-2/3
х=3/3-2/3
х=1/3
б)4/5+х=1/2
х=4/5-1/2=8/10-5/10
х=3/10
в)7/20+х=1/3
х=7/20-1/3=21/60-20/60
х=1/60
г)-5/16+х=17/18
х=17/18+5/16=136/144+45/144
х=181/144=1 37/144
д)х-17/18=-10/9
х=-10/9+17/18=-20/18+17/18
х=-3/18=-1/6
е)2/5-х=1/3
х=2/5-1/3=6/15-5/15
х=1/15
ё)-8/9-х=17/18
-х=17/18+8/9=17/18+16/18
х=-33/18=-1 15/18
ж)-7/9-х=13/18
-х=13/18+7/9=13/18+14/18
х=-27/18=-1 9/18=-1 1/2