A) 3(x-7)-(9-2x)=2(12-x)-(x-10)
3(х-7)-(9-2х)=2(12-х)-(х-10) 3х-21-9+2х=24-2х-х+10 5х-30=-3х+34 5х+3х=34+30 8х=64 х=64/8 х=8