已知x=2007,y=2008,则x2+2xy+y25x2−4xy÷x+y5x−4y+x2−yx=______.
问题描述:
已知x=2007,y=2008,则
÷
x2+2xy+y2
5x2−4xy
+x+y 5x−4y
=______.
x2−y x
答
÷
x2+2xy+y2
5x2−4xy
+x+y 5x−4y
=
x2−y x
×(x+y)2 x(5x−4y)
+5x−4y x+y
=
x2−y x
+x+y x
=
x2−y x
=1+x=2008.x+x2
x
故答案为:2008.
答案解析:利用两个分式相除的法则把要求的式子化为
×(x+y)2 x(5x−4y)
+5x−4y x+y
,约分化简可得结果.
x2−y x
考试点:函数的值.
知识点:本题主要考查求函数的值的方法,式子的变形是解题的关键,属于基础题.