A．
3 5
B．?3 5
C．?5 312 D．
5 32．计算：
(1) (a?b?c)(a?b?c)
(2) 1?(?13)
x2?xy?y2,y?3．设x?，求代数式的值．
x?y3?23?211aba2?b24．当3a?ab?2b?0(a?0,b?0)，求??的值．
baab225．设x、y为实数，且xy?3，求x6．已知a?yx的值． ?yxy111 x?20,b?x?19,c?x?21，求代数式a2?b2?c2?ab?bc?ac的值．
2020205?142，求x?x?2x?1的值． 247．设x?8．展开(x?2)
9．计算(x?1)(x?2)(x?3)(x?4)
10．计算(x?y?z)(?x?y?z)(x?y?z)(x?y?z) 11．化简或计算：
(1) (18?4113 ?)?232?3
(2) 221 ?2?(2?5)2?35?2 (3)
xx?xyx?xy?y? 2xy?yxx?yy
(4) (a?b?aba?b)?(aab?b?bab?a?a?bab)
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第一讲 习题答案 A组
1． C 2． A
3． (1) x?9y?16z?6xy?8xz?24yz
(3) ?3ab?3ab
22222
(2) 3a?5ab?3b?4a?2b?1 (4)
22
13a?16b3 44．?2a?2a ??a 5．mm 2xy B组
2(a?b)2 ??1
a?b21． D 2．a?c?b?2ac,32?23 3． ?4．?3,2
43133 65．?23
2 6． 3
7．3?5
8．x?8x?24x?32x?16 9．x?10x?35x?50x?24
10．?x?y?z?2xy?2xz?2yz
44422222243243x?y11．?3,,,b?a 3y
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