3xy+2x^2-0,5y x=1,5 y=-5/6
3*1,5*(-5/6)+2*(1,5)^2-0.5*(-5/6)=45/10*(-5/6)+4.5+5/10*5/6=-225/60+45/10+25/60=(-225+270+25)/60=70/60=7/6