(x-1/2y-1)(x-1/2y+1)-(x-1/2y+1)^2,其中x=1.5,y=3.9,先化简再求值过程详细,请各位大神帮_数学解答

(x-1/2y-1)(x-1/2y+1)-(x-1/2y+1)^2,其中x=1.5,y=3.9,先化简再求值
过程详细,请各位大神帮帮忙

人气：111 ℃　时间：2020-10-02 00:35:45

解答

(x-1/2y-1)(x-1/2y+1)-(x-1/2y+1)²=(x-1/2y）²-1²-(x-1/2y+1)²=（X-1/2y)²-1-[(x-1/2y)²+2(x-1/2y)+1]=（X-1/2y)²-1-(x-1/2y)²-2(x-1/2y)-1=-2-2(x-1/2y)=-2-2x+y把数值代...