计算:y2−x25x2−4xy÷x+y/5x−4y.
问题描述:
计算:
÷
y2−x2
5x2−4xy
. x+y 5x−4y
答
原式=-
•(x+y)(x−y) x(5x−4y)
5x−4y x+y
=-
x−y x
=
.y−x x