化简,求值4xˆ2y-[6xy-2（4xy-2）-xˆ2y]+1 其中x=-1/2,y=1

化简,求值4xˆ2y-[6xy-2（4xy-2）-xˆ2y]+1 其中x=-1/2,y=1
化简,求值4xˆ2y-[6xy-2（4xy-2）-xˆ2y]+1 其中x=-1/2,y=1

化简,求值4xˆ2y-[6xy-2（4xy-2）-xˆ2y]+1 其中x=-1/2,y=1
4xˆ2y-[6xy-2（4xy-2）-xˆ2y]+1
=4xˆ2y-6xy+8xy-4+xˆ2y+1
=5x²y+2xy-3
=5×1/4×1+2×(-1/2)×1-3
=5/4-1-3
=-2又3/4

4xˆ2y-[6xy-2（4xy-2）-xˆ2y]+1
=4x^2y-(6xy-8xy+4-x^2y)+1
=4x^2y-6xy+8xy-4+x^2y+1
=5x^2y+2xy-3
代人
=5*(-1/2)^2*1+2*(-1/2)*1-3
=5/4-1-3
=-11/4

原式=4x^2y-(6xy-8xy+4-x^2y)+1
=4x^2y-6xy+8xy-4+x^2y+1
=5x^2y+2xy-3
把x=-1/2,y=1代入原式 =5*(-1/2)^2*1+2*(-1/2)*1-3
=5/4-1-3
=-11/4