已知4x2+y2-4x-6y+10=0,求(23x9x+y2xy3)-(x21x-5xyx)的值.-数学

题目简介

已知4x2+y2-4x-6y+10=0,求(23x9x+y2xy3)-(x21x-5xyx)的值.-数学

题目详情

已知4x2+y2-4x-6y+10=0,求(
2
3
x
9x
+y2
x
y3
)-(x2
1
x
-5x
y
x
)的值.
题型:解答题难度:中档来源:不详

答案

4x2+y2-4x-6y+10=0变形得:
4(x-class="stub"1
2
)2+(y-3)2=0,
则x-class="stub"1
2
=0且y-3=0,
解得:x=class="stub"1
2
,y=3,
则原式=(2x
x
+
xy
)-(x
x
-5
xy

=2x
x
+
xy
-x
x
+5
xy

=x
x
+6
xy

=class="stub"1
2
×
class="stub"1
2
+6×
class="stub"3
2

=
2
4
+3
6

更多内容推荐