内容正文:
!10"# 151+230(2)
【
!"#$
】
L5MNI)34
1.'(<{?7¡ÝZ£¤<!"#@(C )
①(狓-
1
2
狔)(-狓+
1
2
狔),
②(3犪-犫犮)(-犫犮-3犪),
③(3-狓+狔)(3+狓+狔),
④(100+1)(100-1).
A.17 B.27 C.37 D.47
2.10
1
10
×9
9
10
= (10)
2-(
1
10
)2=99
99
100
.
3.(1)|}(狓+狔)(狓-狔)-3狔
2
#$%.
: 狓
2
-4狔
2
;
(2)|}狓2-(狓+2)(狓-2)#$%& 4 .
4.µ¡ÝZ£¤<!":
(1)9.9×10.1;
!
:
"#=(10-0.1)(10+0.1)
=100-0.01
=99.99;
(2)98×102;
!
:
"#=(100-2)(100+2)
=10000-4
=9996;
(3)(犿+狀)(犿-狀)-狀(2犿-狀);
!
:
"#=犿2-狀2-2犿狀+狀2
=犿2-2犿狀;
(4)99×101×10001
!
:
"#=(100-1)(100+1)×10001
=(1002-1)(1002+1)=1004-1
=99999999.
5.¥|},¦=D:(2狓-狔)(狔+2狓)-(2狔+狓)
(2狔-狓),A?狓=1,狔=2.
!
:
"#=4狓2-狔
2-(4狔
2-狓2)
=4狓2-狔
2-4狔
2+狓2
=5狓2-5狔
2,
.狓=1,狔=25,
"#=5×12-5×22=5-20
=-15.
【
!"#,
】
L5MNI)74
6.BC犪2-犫2=10,q犪+犫=-2,0犪+犫#D& (D )
A.8 B.12 C.5 D.-5
7.!":892-992= -1880.
8.!":
(1)(狓-狔+狕)
2-(狓+狔-狕)
2;
!
:
"#=[(狓-狔+狕)+(狓+狔-狕)][(狓-狔+狕)-
(狓+狔-狕)]
=4狓狕-4狓狔;
(2)
12-22
1+2
+
32-42
3+4
+
52-62
5+6
+ …
+
992-1002
99+100
.
!
:
" # =
(1+2)(1-2)
1+2
+
(3+4)(3-4)
3+4
+
(5+6)(5-6)
5+6
+ …
+
(99+100)(99-100)
99+100
=-1-1-1…-1
=-50.
9.RN:|T犿 .�_9�,-�<(4犿+5)2
-97ñ8_¶.
¤¥
:(4犿+5)2-9
=[(4犿+5)+3][(4犿+5)-3]
=8(犿+2)(2犿+1),
(�¦犿/§�45,̈ C#(4犿+5)2-9u©8�ª.
【
!"#2
】
L5MNI)PQRS
10.V�,pß.犪#)Z;?xy67pß.
犫#p)Z;,·'�ü)d¸367P¹
º;
,
µ¡ºh»�;+"
,
7QR¼�#
9£¤<
? (A )
A.犪2-犫2=(犪+犫)(犪-犫)
B.(犪+犫)2-(犪-犫)2=4犪犫
C.(犪+犫)2=犪2+2犪犫+犫2
D.(犪-犫)2=犪2-2犪犫+犫
2
·91·
11.(1)�9<(犿-2)(犿+2)(犿2+4)-(犿4-
16)#$%. (A )
A.0 B.4犿 C.-4犿 D.2犿4
(2)'+!"(-7+犪+犫)(-7-犪-犫))*
#&
(A )
A.Û<=[(-7)+(犪+犫)][(-7)-(犪+
犫)]=72(犪+犫)2
B.Û<=[-(7+犪)+犫][-(7+犪)-犫]=
(7+犪)2-犫2
C.Û<=[-7+犪+犫][-7-(犪+犫)]=72
-(犪-犫)2
D.Û<=(-7+犪+犫)[-7-(犪-犫)]=72
+(犪+犫)2
12.(1)/狓犿-狔
狀=(狓+狔
2)(狓-狔
2)(狓2+狔
4),
0犿= 4 ,狀= 8 .
(2)/狓2-狔
2=8,狓2-狕2=5,0(狓+狔)(狔+狕)(狕
+狓)(狓-狔)(狔-狕)(狕-狓)= 120 .
(3)(1-
1
22
)(1-
1
32
)(1-
1
42
)…(1-
1
992
)(1
-
1
1002
)
#$%&
101
200
.
13.!":
(1)(犪+1)(犪-1)(犪2+1)(犪4+1)(犪8+1);
!
:
"#=(犪2-1)(犪2+1)(犪4+1)(犪8+1)
=犪16-1;
(2)[2犪2-(犪+犫)(犪-犫)][(犮-犪)(犮+犪)+
(犫-犮)(犮+犫)];
!
:
"#=(犫