内容正文:
!8"# 14/0()*(3)
【
!"#$
】
K1I*JK1I
1.(1)!"(狓-1)(狓+2)#$%& (A )
A.狓2+狓-2 B.狓2-狓-2
C.狓2+2 D.狓2-2
(2)(狓+1)(2狓-5)#!"$%& (A )
A.2狓2-3狓-5 B.2狓2-6狓-5
C.2狓2-3狓+5 D.狓2-3狓-5
(3)!"(3犿+5)(-3犿-5)#$%& (C )
A.9犿2-25 B.-9犿2-25
C.-9犿2-30犿-25 D.-9犿2+30犿-25
(4)'(!"$%&狓2-7狓+12#& (C )
A.(狓+3)(狓+4) B.(狓-3)(狓+4)
C.(狓-3)(狓-4) D.(狓+3)(狓-4)
2.!":(1)(2犪-3犫)·(3犪-2犫)#$%&: 6犪
2
-13犪犫+6犫2 ;
(2)!":(-2犪-0.5犫)(犪-2犫+1)=
-2犪
2+3.5犪犫+犫2-2犪-0.5犫.
3.!":
(1)(犪+1)(犪-6);
!
:
"#=犪2-6犪+犪-6
=犪2-5犪-6;
(2)(2狔+3)(狔-1);
!
:
"#=2狔
2-2狔+3狔-3
=2狔
2+狔-3;
(3)(犿+2狀)(2犿-狀);
!
:
"#=2犿2-犿狀+4犿狀-2狀2
=2犿2+3犿狀-2狀2;
(4)(狓+3狔-4)(2狓-狔).
!
:
"#=2狓2-狓狔+6狓狔-3狔
2-8狓+4狔
=2狓2+5狓狔-3狔
2-8狓+4狔.
【
!"#,
】
+8)34
4.(1)/(狓-3)(狓-4)=狓2+狆狓-狇,WX狆-狇
#D&
(B )
A.-5 B.5 C.19 D.-19
(2)/2狓+犿 N狓+2#�"?�m狓#6�
�
,
0犿#D. (A )
A.-4 B.4 C.-2 D.2
(3)V%犪2-2犪-1=0,WX�9<(犪-3)(犪+
1)#D& (B )
A.2 B.-2 C.4 D.-4
5.V�,¡�9<¥¦���ü+". (C )
A.犪犮+犫犮
B.(犪-犮)(犫-犮)
C.犪犮+(犫-犮)犮
D.犪+犫+2犮(犪-犮)+(犫-
犮)
6.!":
(1)(3犪+1)(2犪-3)-(6犪-5)(犪-4);
!
:
"#=6犪2-7犪-3-(6犪2-29犪+20)
=22犪-23;
(2)3(2狓-1)(狓-3)-2(3狓-2)(2狓-3).
!
:
"#=3(2狓2-6狓-狓+3)-2(6狓2-9狓-4狓+6)
=6狓2-21狓+9-12狓2+26狓-12
=-6狓2+5狓-3.
7.YZ[:
(狓-1)(狓-2)=(狓+3)(狓-4)+20.
!
:
"jk��/
:狓2-3狓+2=狓2-狓-12+20,
�-'
:-2狓-6=0,
!'
:狓
=-3.
·51·
8.(1)/��犪~�D,-�<犪3+2犪2-犪-2N
(犪2-犿犪+2狀)(犪+1)�OP,0犿、狀#Düw
.
(A )
A.-1,-1B.-1,1 C.1,-1 D.1,1
(2)V%(2狓+1)(犿-狓)#kl<¸@h�,0
�9犿#D. (C )
A.0 B.1 C.0�
1
2
D.0�1
(3)/(狓+犿)(狓2+狀狓+1)#kl<?�9�
.-2,q�m狓2 �,0kl<?#6��e9
.
(D )
A.-2 B.2 C.3 D.-3
9.pÏJp�üw!"t62_<�¤m:(2狓+
犪)(3狓+犫),pÏäU�\°67-�<?犪#
��
,
×�#$%.6狓2-13狓+6,p�äU�
\°�z7-�<?#狓#e9,×�#$%
.2狓2-狓-6,0º2m#)*$%& 6狓
2+
5狓-6 .
10./(狓2+狆狓-
1
3
)(狓2-3狓+狇)#"?�m狓
�N狓3 �.
(1)=狆、狇#D;
(2)=�9<(-2狆
2
狇)
2+(3狆狇)
0+狆
2019
狇
2020
#D.
!
:(1)(狓2+狆狓-
1
3
)(狓2-3狓+狇)
=狓4-3狓3+狇狓
2+狆狓
3-3狆狓
2+狆狇狓-
1
3
狓2+狓-
1
3
狇
=狓4+(狆-3)狓
3+(狇-3狆-
1
3
)狓2+(狆狇+1)狓-
1
3
狇,
∵(狓2+狆狓-
1
3
)(狓2-3狓+狇)2s�*�狓C)狓
3
C
,
∴狆狇+1=0,狆-3=0,∴狆=3,狇=-
1
3
;
(2)∵狆=3,狇=-
1
3
,
∴(-2狆
2
狇)
2+(3狆狇)
0+狆
2019
狇
2020
=4狆
4