1) х(7+3)-4х=8х+17+36-5х 7х+3х-4х=8х+17+36-5х 6х=3х+53 6х-3х=53 3х=53 х=53:3 3х(7+5)+6х-34=5х+3х-4х+36+21 21х+15х+6х=4х+57 42х=4х+57 42х-4х=57 38х=57 х=57:38 х=1,5