八年級(jí)數(shù)學(xué)下《分式》基礎(chǔ)練習(xí)題

--------．

．．．

．

．． ．． ．．． ．2x． ．

． ．x

．3x6 3x17.當(dāng)x＝ _＿時(shí),分式x21的值為0．8．當(dāng)ｘ= 時(shí),(x2)(x的值為０.． ．．．x1 ．．．．． ．x2 ．．．．．．a(chǎn)

． ．．

a1?． ?． ．．x

2

x1

．

ab

．3 3x2

a2b212x1值為０

D.x≠yx2y2

有意義2．．．．4x

．．． ．．y

．．．．x ．

．．．．．x51２．當(dāng)x＜0時(shí),|x|的值為（ ）A.１; B．－1； C.±1； Ｄ.不確定．．．．x ．．．． ．．． ． ．．．．．． ．．．x21

x1

x1Ｄ．

x111．．

x x21．

．x

x21．

A

AMx．x

BM．2．x1

1x

３．( )

5xy2.

4.1

( ) .5.1

( )2 ( )

．．3x

3x2y

．xy x2y2．

2 4y26．化簡(jiǎn)分式:（１）

xy

_＿

x29

．．．．．．．．．．．(y x)

3 6xx2

．．．．(1

m n (

) nm

;(2

2a1(

) 12am n mn 2b ．a(chǎn)2 ab 2b2 (

1 a．

a b

b ( ) .2 2 a

1 b

b a二、選擇題： 9．把分

a29

約分得（ ）．．．．．．

．．．． ．A．a(chǎn)3

Ｂ.a3a3

D．a(chǎn)3b3

．b b10．如果把分式

x2

b中的ｘ和y都擴(kuò)大10b．．．．．．．xy

．．．．．．．

．3amaa3

0 C．a(chǎn)b1b1

xy 1bm b

ab ac1 c1

x2y2 xy2x．

．． ．xy． ． ． ．1３．化簡(jiǎn)

a2b2

的正確結(jié)果是（)A.ab

ab

11ab ab 2ab 3．．．a(chǎn)22abbab ab 2ab 31４.化簡(jiǎn)分式

9a2b2

后得( ）A.

3a2b2

B.3ab

Ｃ．3ab

Ｄ． 22．．．a(chǎn)b6ab2 ．． ．a(chǎn)b2ab2

．a(chǎn)6ab2

a

．．a(chǎn)b．．m三、解答題：10．約分:(1)10ab? ．．m

16x2y

(3）

m1．．．．．．．．．．1ac． 32x3y ．

21（４)

y24xy4x2

(5)m24m

(6)x24x42xy m2

．．x2．一、填空題:1．8x

9y) ＿_(dá) ＿＿．

x2xy3x3y _．y

2x3

．．．． ．x2 3x

．．． 3．1

(ab) ＿． 4．

abb2

a2b2

_＿

＿_(dá).b

．．．． a22abb2

a2ab

5.已知x＝2008,y=２00９，則(xy)(x2y2)的值為 .．．．．

x4y4

．．．a(chǎn)

(nm)

．2a ．

B．a(chǎn) ．

a ．

am2n2

mn

mn

mn

mn7．計(jì)算

ab2

3ax等于(

）A．2b

? B．3b2

? C．2b2

? D．2b2x

4cd

3x． 2 ．

3x．

8c2d28.x>1|1x|得（

)Ａ.1 Ｂ．-１ Ｄ．0．1x

．． ． ．． ．．．． ．．９．計(jì)算(x3)(x2．．．． x21

x3x2x

． ．x2x

x1

x2

D.x22xx2

．x22x．x2x

．x1． ．1 1 1 1Amnnm ? mnnm

C．mm 1? m3 m21．

m m m5y1．

21xy

m24n2１．．．１

m22mn

3

x21 1 128x2

m2

mn

(x1)2 x1 x1x(3a2) 25a2b2

. a4．

5ab

4x29a2x2

16)

a4?16.

(1a)2

aa2a2)

aa2a4a2b2 a2ab b2 2x6 x2aa2a

2abb

2 b2

?

44xx2

(x3)2

3x．2a3

．3x22.( )3bc2

．．．．

32y2

z

．．2a(b)3． 2a2a6

6a5

C．8a5

8a6．33 323．．．． ．．．．．．Ａ．x3y3 ．．

Bm6．m2

m3

Ｃ．a(chǎn)2b2aab

D(ab)3(ba)2

ab6．n

m2

的結(jié)果是( )Ａ.m

m2

n

－nm2 m2 n2 ．n2 n3 ．m4

．(2a)3(b)2(b)． ．b2 a aab6．2a2b

8a3b62xy

C.1a2． b5．

16a2b5y3

2a 4a3( )33c

)25a2

．(2y2)2? ( 8xb28x

( )2b．（1)4x214x24x1,其中 124x

x 4（２）a4a2b2

a(ab).b2

,其中a

1,b＝－1．．．．(ab)2

b2 a ．． 2m24m4 m22m m

．

m24

( m2 )2(2)3．．．

2a

, 9ac2

．．

x12x2

4,x1．3x 4x3． ．． m

, n

．a(chǎn)(m2)b(m2)．x , y ．

_．a(chǎn)(xy)b(yx)．． ．．

．

．12．

2 ．2

3 5

．．a(chǎn)29 3a

3a2

6ab．

x,1

11

． ．A.11

Ｃ.

x 2x 3x11．2x

6x

．6xx3a3 a3y3 x3y3

．xy

yx

．

．xy

B．

C?．

．bca的計(jì)算結(jié)果是（ ）．． ．．．．．．． ．a(chǎn) b cA.b2c2a2

?B.b2cac2a2b

C.b2cac2a2b

?? D．bca． abc

abc

． abc

．a(chǎn)bc１2.3

等于（ )Ａ．a(chǎn)22a6? Ｂ.a24a2?Ｃ.a24a4

Ｄ.aa1

a

．．． ．．．

1a

．

a1

．

a1

1a．13．x22x4

x2 ?

x24

x2x62x22x5．．x2

2x．

．．x

x3

3x7．

3 12

y x6．2x4 x2 x24 x2xy y2xy

x1

x )1,．x2x x22x1 x

B

5x4

,．x5

x

x23x10．1．化簡(jiǎn)

9a2b2

＿

6ab

= ＿ ．3

y )的結(jié)果是＿ ＿ ．．．a(chǎn)2b6ab2 ．．．．2a4a2．．．y xy ．．．．．．．1 1 )(m21)的結(jié)果是＿ ＿_(dá).５．a(chǎn)

ab．．．m1 m1

ab

ab6．12

2 2

．．．m2

3m m37．x

x2y2

的結(jié)果是（ ）．．．．．．．．x y

x2y2

．．．．． ．x2y2 B.x2y2

C.(xy)2

D.(xy)2y)2y)2

．x2y2

．x2y2ab b 1 ab ab 1．．．．8b )2．．．．

a2b2

．

．babb2

Cab．

b(ab)ab

ab

ab ab ab ab( )2( )2

．

．

．．

．( )

．a(chǎn)b ab ab．

ab

ab

ab．1 x

9．2 12

x2 4 ?x1 1x

m3 9m2

x211．(a

1 )

a2a1

12.(m

mn)(m

mn)? 13.( a

1)

3a2)．． 1a

a22a1

．． mn mn ．

a1

1a2(

y2 1y )y4

51

1)(x4

x2x2)y22y y24y4 y

x 1

x21[

2 xy (

xy)]

xy,．．．3x xy 3x x．．．1． 2 1

7． ．

1x x1 x211 1． _．

x

x2

．．x1．1

x1

3．．

x5．

x6x2 x23x a．

1． ．．2x7 72x．21m x

3．

xx

2

ax

．． ．Ａ．1x1

3x 4

x3x2

x 5．．x

．x21

4 5

x6． ．Ａ．x34

x5nn

Ｂ.xa

xb

C.(x1)21

D．xnx．．3

5 b b a

．m n2 02y2 y

12

43y42y

． ．．．1．x1x3． ． x ．1

．

．x2 x4 21

2

4x．

．

B．

．．/