求6x²y+2xy-3x²y²-7x-5yx-4y²x²-6x²y得值,其中|x+3|+(y-½)²=0

来源：学生作业学帮网编辑：学帮网时间：2024/06/29 03:13:19

6x²y+2xy-3x²y²-7x-5yx-4y²x²-6x²y |x+3|+(y+1/2)²=0 x=-3 y=1/2
=-3xy-7x²y²-7x=-x(3y+7xy²+7)=3(3/2-21/4+7)=12