题目
题型:填空题难度:简单来源:不详
答案
=x2-2(y+1)x+y2+2y+1+2y2-4y+2
=x2-2(y+1)x+(y+1)2+2(y-1)2
=(x-y-1)2+2(y-1)2.
∴原式大于或等于0.
故本题答案为:大于或等于0.
核心考点
举一反三
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a2-4 | ||
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(2)若|a-5|和(b+4)2互为相反数,则[
4ab |
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______.
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(x2-1)2+ 题型:xy|-2| |
(x+1)(y+2) |
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(x+1)(y+1) |
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(x+2001)(y+2001) |
A.
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