计算:y-x分之x+y+x-y分之y-y-x分之2x-y
问题描述:
计算:y-x分之x+y+x-y分之y-y-x分之2x-y
答
(x+y)/(y-x) +y/(x-y) -(2x-y)/(y-x)
=(x+y)/(y-x)- y/(y-x) -(2x-y)/(y-x)
=[(x+y)-y -(2x-y)]/(y-x)
=(y-x)/(y-x)
=1