6mx^2+4nxy+2x+2xy-x^2+y+4=6mx^2-x^2+4nxy+2xy+2x+y+4=(6m-1)x^2+(4n+2)xy+2x+y+4不含二次项,即6m-1=0,m=1/64n+2=0,n=-1/22m^2n+10m-4n+2-2m^2n-4m+2n=2m^2n-2m^2n+10m-4m-4n+2n+2=6m-2n+2=6(1/6)-2(-1/2)+2=1+1+2=...