计算:
(1)(2x+5y)2;
(2)30-2-3+(-3)2-(14)-1;
(3)(m+2n)(n-m);
(4)(x-2y)(x+2y)-(x+2y)2;
(5)(3m-5n)2-(3m+5n)2;
(6)(2x-y+1)(2x+y-1).
3
0
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2
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3
+
(
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3
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2
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(
1
4
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1
【答案】(1)4x2+20xy+25y2;
(2);
(3)2n2-mn-m2;
(4)-8y2-4xy;
(5)-60mn;
(6)4x2-y2+2y-1.
(2)
5
7
8
(3)2n2-mn-m2;
(4)-8y2-4xy;
(5)-60mn;
(6)4x2-y2+2y-1.
【解答】
【点评】
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发布:2025/6/10 10:30:1组卷:1105引用:2难度:0.5