4x²y-[6xy-2(4xy-2)-xy²]+1=4x²y-(6xy-8xy+4-xy²)+1=4x²y-6xy+8xy-4+xy²+1=4x²y+2xy+xy²+1=xy(4x+2+y)+1=(-2)×2×[4×(-2分之1)+2+2]+1=-4×2+1=-7可以把化简的式子和求值的式子分开再算一遍吗，谢谢4x²y-[6xy-2(4xy-2)-xy²]+1=4x²y-(6xy-8xy+4-xy²)+1=4x²y-6xy+8xy-4+xy²+1=4x²y+2xy+xy²+1=xy(4x+2+y)+1把x=-2分之1，y=2带入式子得：=(-2分之1)×2×[4×(-2分之1)+2+2]+1=-1×2+1=-2居然看错了！