内容正文:
!9"# 151+230(1)
【
!"#$
】
L5MNI
1.(1)!":(犪+1)(犪-1)#$%& (B )
A.犪2+1 B.犪2-1 C.犪2 D.2犪
(2)|}(-2狓-3)(3-2狓)#$%& (A )
A.4狓2-9 B.9-4狓2
C.-4狓2-9 D.4狓2-6狓+9
(3)'(><!")*#& (D )
A.(狓-3)(狓+4)=狓2-12
B.(
2
3
狓+3)(
2
3
狓-3)=
2
3
狓2-9
C.(犪+5)(犪-5)=犪2-10
D.(2狓狔-
1
2
)(2狓狔+
1
2
)=4狓2狔
2-
1
4
2.'("<7¡ÝZ£¤<!"#& (B )
A.(3犪+犫)(3犫-犪)
B.(
1
3
-1)(-
1
3
-1)
C.(狓-狔)(-狓+狔)
D.(-犪-犫)(犪+犫)
3.(1)(-犪+
1
5
)(-犪-
1
5
)= 犪
2-
1
25
;
(2)(-犪-5)( -5+犪 )=25-犪
2;
(3)(-2犪2-5犫)( -5犫+2犪
2) =25犫
2-4犪4.
4.!":
(1)(犪+5)(犪-5);
!
:
"#=犪2-25;
(2)(狓-2狔)(2狔+狓);
!
:
"#=狓2-4狔
2;
(3)(3犿-2狀)(-3犿-2狀);
!
:
"#=4狀2-9犿2;
(4)(5犪犫-3狓狔)(-3狓狔-5犪犫);
!
:
"#=9狓2狔
2-25犪2犫2;
(5)(狓3+2)(狓3-2).
!
:
"#=(狓3)2-22
=狓6-4.
【
!"#,
】
NI)OH34
5.(1)BC犪2-犫2=8,q犪-犫=-4,0犪+犫#D
&
(D )
A.4 B.12 C.2 D.-2
(2)/犪+
犫
4
=3,犪-
犫
4
=7,0
1
16
犫2-犪2=
(B )
A.21 B.-21 C.10 D.-18
6.(1)BC狓2-狔
2=2019,狔=狓-3,0狓+狔=
673 ;
(2)BC狓+狔=3,狓-狔=5,02狔
2-2狓2
= -30 .
7.!":
(1)(1+狓)(狓-1)(狓2+1);
!
:
"#=(狓+1)(狓-1)(狓2+1)
=(狓2-1)(狓2+1)
=狓4-1;
(2)(3犿-4狀)(4狀+3犿)-(2犿-狀)(2犿+狀);
!
:
"#=9犿2-16狀2-4犿2+狀2
=5犿2-15狀2;
(3)¥|},¦=D:
(狓+2狔)(狓-2狔)-(2狓-狔)(-2狓-狔),A?狓
=8,狔=-8.
!
:
"#=狓2-4狔
2-狔
2+4狓2
=5狓2-5狔
2,
?@�L'"#=0.
8.§¨h©üwª犃、犅 h�t�`úO«F
¬
,
§©p�¬
(2狓+3)犽犿,̈ ©p�¬
(3狓-1)犽犿,®x(5狓-2)犺h§、̈ h©O
�
,
l犃、犅h�O¯-.*¹?
!
:[(2狓+3)+(3狓-1)](5狓-2)
=25狓2-4(h )
M
:犃、犅D¡+¢(25狓2-4)h
.
·71·
9.(1)V%9狓2-16狔
2=(-3狓-4狔)·犕,WX
犕 ¥¦#<{. (C )
A.3狓+4狔 B.3狓-4狔
C.4狔-3狓 D.-4狔-3狓
(2)V%(2犪+2犫-3)(2犪+2犫+3)=40,0犪
+犫#D. (C )
A.
7
2
B.-
7
2
C.±
7
2
D.±3
10.(1)(犪犿-1+犫狀+2)(犪犿-1-犫狀+2)= 犪
2犿-2-
犫2狀+4 ;
(2)(狓-1)(狓2+1)( 狓+1 )=狓
4-1.
11./狓2-狔
2=-1.0(狓-狔)
2021(狓+狔)
2021=
-1 .
12.V%67°_97¥¦.h74±)_9
#ÝZ£
,
WX²º7°_9.
“
Ý£9
”,
“
Ý£9
”
¡P<,1¥¦`y.�V:-3
=12-22;-5=22-32;-7=32-42;…§
ª^�p³(#I@
“
Ý£9
”
?
,-3&�
67
“
Ý£9
”;-5&�z7“Ý£9”;-7
&�n7
“
Ý£9
”;…;
0�20197“Ý£
9
”
& -4039 ,�狀7“Ý£9”¡ÝZ
£#;<,¥¦. 狀
2-(狀+1)2 .
13.!":
(1)(狓-狔)(
1
9
狓-狔)-(
1
3
狓-狔)(
1
3
狓+狔).
!
:
"#=(狓-狔)(
1
9
狓-狔)-(
1
9
狓2-狔
2),
=2狔
2-
10
9
狓狔.
(2)|}=D:
(犿2-狀2)