==================================
1.4х-3.5\0.5=2.3х-9\-1.5 0.5*(2.3х-9)=-1.5*(1.4х-3.5) 1.15х-4.5=-2.1х+5.25 1.15х+2.1х=5.25+4.5 3.25х=9.75 х=9.75:3.25 х=3