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> 若m-1+n-1=(m+n)-1,则m-1n+mn-1=______.-数学
若m-1+n-1=(m+n)-1,则m-1n+mn-1=______.-数学
题目简介
若m-1+n-1=(m+n)-1,则m-1n+mn-1=______.-数学
题目详情
若m
-1
+n
-1
=(m+n)
-1
,则m
-1
n+mn
-1
=______.
题型:填空题
难度:偏易
来源:不详
答案
由m-1+n-1=(m+n)-1得
class="stub"1
m
+
class="stub"1
n
=
class="stub"m+n
mn
=
class="stub"1
m+n
,
所以,(m+n)2=mn,
整理得,m2+2mn+n2=mn,
所以,m2+n2=-mn,
m-1n+mn-1=
class="stub"n
m
+
class="stub"m
n
=
m
2
+n
2
mn
=
class="stub"-mn
mn
=-1.
故答案为:-1.
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题目简介
若m-1+n-1=(m+n)-1,则m-1n+mn-1=______.-数学
题目详情
答案
所以,(m+n)2=mn,
整理得,m2+2mn+n2=mn,
所以,m2+n2=-mn,
m-1n+mn-1=
故答案为:-1.