（先化简,再求值）3x²y-【5x²y+2（x²y-1/2）+x²y】+6x²y的值,其中x=-2,y=1/2

来源：学生作业学帮网编辑：学帮网时间：2024/06/05 12:51:34

3x²y-【5x²y+2（x²y-1/2）+x²y】+6x²y
=3x²y-【5x²y+2x²y-1+x²y】+6x²y
=3x²y-8x²y+1+6x²y
=x²y+1
=(-2)²*(1/2)+1
=4*1/2+1
=2+1
=3