内容正文:
计算专练之分式和分式方程2025-2026学年
冀教版八年级上册
板块一:分式的乘除与乘方
1.计算:
1竖32x2
÷X
x2-1rx-1
2.计算:
4)8x2
÷6x
(2)2n÷m2-4nt4
x2+2x+1x+1
m+2m2-4
3.计算:
e6g扩
a+b a2-b2
4.计算:
0签(@
16a
x2-2x+1x-11+x
5.计算:
(1),a+2a2-4a+4a2-4
2)2-12x2-2
a2-2a+1a+1a2-1
x+2x+14r2+8x+4x-.
板块二:分式的加减
1.计算
(1)2a-1.a-4
(2)1.1
a+3a+3
x+2x+3
2a2t6ab:(2)x3
2.计算:(1)
.1
x-3x+3
3.计算:
(1)
2a
(2)x+2y+y2x
a2-42-a
y-x x-y y-x
4.计算:
(1)2x1
x2-1x-1
2)2+2x+1+2-1x
x+2x-1x+2
板块三:分式混合运算
1.计算:
2.化简:-2m÷(11).
m2-6m+9`m-3m+3
3.计算
1)1x2-1.1
xx+1x2-2x+1
(2)2g-6÷5
x-2
-2-2).
4.化简:
(1)
a21
(2)
m-3-7)sm2-4m
a-1a-1
m+3
2m+6
5.分式化简:
(10-1.x2-1
x+2x+2
e
6.计算:
(2)
2c3)2
5a
3ab2
2b3
板块四:分式化简求值
1.先化简,再求值:-6r+9÷-3江,其中,x=3.
x2-1x+1
2.先化简,再求值:
(名+2x英=2
3.先化简,再求值:1-x-2-5÷-6r+9,其中=2.
x+2
x+2
4先化简,再求值:子1:盏1,
然后x在-1,0,1,2四个数中选一个你认为合适
x+1x2+2
的数代入求值.
5.先化简,再求值:(2a12)÷)a4一,其中a满足+2a-3=0.
a+2
a2+4a+4
6.已知A=+2x+1x
x2-1x-1
(1)化简A;
(2)当x满足x=3
是x-12x-22时,A的值是多少2
板块五:分式方程
1.解方程:2=3
x-3 x
2品
2.解方程:x
3解方程:-舜=总
4.解分式方程:
(1)1.2
xxt3
2器21
5.解分式方程:
x1x212)3-1
(1)x+1.2
x-22-x
【答案】
计算专练之分式和分式方程2025-2026学年
冀教版八年级上册
板块一:分式的乘除与乘方
1.计算:
10怒y.2)2
2x3
÷X
3y
x2-1x-1
【答案】解:(1)原式=
3x2
(2)原式=
2
(x+1j(x-1)X名
xx+1
2.计算:
1)8x2
÷6x
x2+2x+1x+1
(2)2=n÷m2-4nt4
m+2
m2-4
【答案】(1)4x
(2)-1
3x+3
【解答】(1)原式=
8x2
x+1
x2+2x+16x
-8x2-(x+1)
(x2+2x+1)6x
4x(x+1)
3(x+1)2
4x
3(x+1)
-4x
3x+3
(2)原式=2-n.(m-2)(m+2)
n+2
(m-2)2
=mr2.(m-2)(m+2)
m+2
(m-2)2
=-1;
3.计算:
2aj02〔9g
【答案】(①4a-4b2-8x+16
a+b
x2+4x+4
【详解】(1)解:原式=
8ab6(a+b)2(a-b)214a2-4ab
(a+b)
a2bo
2(a-b)a+b'
(2)原式=x-4-4+2-x-4.x+1.+少K-42-8x+16
(x+I)6(x+1)(x+2)2(x+1)°(x-4)(x+2)2(x+2)2x2+4x+4
4.计算:
2a)2
16a2a6:
②)-1x+1.1-x
x2-2x+1x-11+x
【答案】(①302
1-x
2be
1+x
【详解】(1)解:
3b2 be.(2a
16a 2a2b
3b22a24a2
16a be b2
3a3
26c¥
(2)解:2-1÷x+11-x
x2-2x+1x-11+x
(x+1(x-1x-11-x
x-1)2
x+11+x
=1-x
1+x
5.计算:
(1)a+2
a2-4a+4.a2-4
(2)
a2-2a+1a+1
a2-1
-1÷2-2x-1.
x2+2x+14x2+8x+4
【答案】(1)0-2
2
a-斤2F-2x+1
【解折】解:(①原式=a+2a-2.a+1川a--4-2
(a-l2a+1(a+2(a-2)a-1
(2)原式=
(x+1(x-14(x2+2x+112
(x+1)
2(x2-1(x-12x2-2x+1
板块二:分式的加减
1.计算
(1)2a-1.a-4
(2)1
1
a+3a+3
x+2x+3
【答案】解:(1)原式=2a-1-(a-4)
a+3
=a+3
a+3
=1;
x+3
x+2
(2)原式=(x+2(x+3)(x+2)(x3】
(x+2)(x+3)
2.计算:(1)b+1
2a26ab
(2)x3
x-3x+3
【答案】解:(1)b+1
2a26ab
32
2.
6ab 6a b
-3b2,
6a2b
(2)x3
x-3x+3
x(x+3)
3(x-3)
(x-3)(x+3)
(x+3)(x-3)
=x2+3x-3x+9
(x-3)(x+3)
x2+9
(x-3)(x+3)
=x29
x2-9
3.计算:
(2)x+2y+y-2x
y-x x-y y-x
【答案】(1)1
+2:(2)1.
【解析】解:(1)原式
2a
-1
2a
-a+2)
-2a-a-2=1
(a+2)(a-2)'a-2(a+2)(a-2)(a+2a-2(a+2(a-2a+2
2)原式=-x-2y+y+2x==y=1.
x-yx-yx-y x-y
4.计算:
(1)2x1
x2-1x-1'
2)+2x+1+2-1x
x+2
x-1x+2
7:2)
【答案】(1)1
2x2+4x+3
x+2
2x
(x+1
【解析】解:(1)原式=
2x-x-1=1
(x+(x-1(x+1(x-1(x+1(x-)x+1
(2)原式
=+-)++x+x41-2++1,+0x+22+4r+3
x+2
x+2x-1x+2
x+2x+2
x+2
板块三:分式混合运算
1.计算:
2y
3x-1
x-y-少:
【答案】(1①)22)-1
【详解】(1)解:
2x 2y
x-y x-y
2x-2y
x-y
2x-2=2
x-y
(2)解:
x-3-
x2-x(x+1
x(x+)_3x-1
x(x-1)(x+1
x+1
x+1x2+x-3x+1
x(x-1)x+1
=x+1.x2-2x+1
x(x-1)x+1
=x+1x-=-l
x(x-1)x+1x
2.化简:6-2m÷(1
1).
m2-6m+9
m-3m+3
【答案】解:原式=2(m3)÷,mt3m3、=,-2(m+3)(m-3)-.3
(m-3)2(m+3)(m-3)(m-3)1
6
3.计算
11x2-1.1
一,2)2x-6÷5。
xx+1x2-2x+1’1
x-2
x-2x-2.
【答案】解:(1)原式=1-〔x+1)(x-1),1
x+1(x-1)2
=1.1
x x-1
=x-1-x
x(x-1)
1
x*72
(2)原式=2(x-3)÷5-(x+2)(x-2)
x-2
x-2
=2(x-3).
x-2
x-2-(x+3)(x-3)
2
-x-3
4.化简:
1)2
(2)
a-1a-1
m-3、
7).m2-4m
m+3
2m+6
【答案】(1)a+1,2)2m+8
h
【解析】解:(1)原式=a-1_a+1(a-
a-1
a-1
2=a*1
(2)原式=
m2-97)2(m+3)_(m+4(m-4),2(m+3)_2m+8
+3m+3m(m-4)
m+3 m(m-4)m
5.分式化简:
(1)-1.x2-1
x+2x+29
【答案】(1)1
;(2)2x-1.
x+1
【解析】(1)解:x-1
x+2
1
x+2(x+1(x-1可x+1'