题目内容
先化简
,再从−2,0,1,2中选择一个合适的数代入,求出这个代数式的值.
-1
解析:解:原式=
················ 2’
=
····················· 3’
=
·························· 4’
=
···························· 5’
取x=1代入得,原式=−1
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题目内容
先化简
,再从−2,0,1,2中选择一个合适的数代入,求出这个代数式的值.
-1
解析:解:原式=
················ 2’
=
····················· 3’
=
·························· 4’
=
···························· 5’
取x=1代入得,原式=−1