(1)计算:22-(3-1)0+(12)-1;(2)已知x=2007,y=2008,求x2+2xy+y25x2-4xy÷x+y5x-4y+x2-yx的值.-数学

题目简介

(1)计算:22-(3-1)0+(12)-1;(2)已知x=2007,y=2008,求x2+2xy+y25x2-4xy÷x+y5x-4y+x2-yx的值.-数学

题目详情

(1)计算:22-(
3
-1)0+(
1
2
)-1

(2)已知x=2007,y=2008,求
x2+2xy+y2
5x2-4xy
÷
x+y
5x-4y
+
x2-y
x
的值.
题型:解答题难度:中档来源:南通

答案

(1)原式=4-1+2=5;
(2)原式=
(x+y)2
x(5x-4y)
×class="stub"5x-4y
x+y
+
x2-y
x

=class="stub"x+y
x
+
x2-y
x
(4分)
=
x+x2
x

=x+1.(6分)
∴当x=2007,y=2008时,原式=2007+1=2008.(7分)

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