题目

已知X2—4X+4与|Y—1|互为相反数则式子（X分子Y减去Y分子X）除（X+Y）的值等于?

提问时间：2020-10-30

答案

x^2-4x+4+|y-1|=0
(x-2)^2+|y-1|=0
(x-2)^2=0,|y-1|=0
x=2,y=1
(y/x-x/y)/(x+y)
=(y^2/xy-x^2/xy)/(x+y)
=[(y^2-x^2)/xy]/(x+y)
=(y-x)(y+x)/xy*1/(x+y)
=(y-x)/xy
=(1-2)/1*2
=-1/2