x+y=0.2,x+3y=1,y=0.4×=-0.23x∧2+12xy+12y∧2=3×0.04-0.96+1.92=1.08
由己知可得,0.2+2y=1,即y=0.4,x=-0.2。则3x^2+12xy+12y^2=3×0.04-12×0.2×0.4+12×0.16=0.12-0.96+1.92=1.08
原式=3(x+2y)²由题知2x+4y=1.2x+2y=0.6所以原式等于3×0.6×0.6=1.08