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

问题描述:

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

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