Toán 8 - Bài tập ôn tập

BÀI TẬP LÀM TRONG DỊP NGHỈ TẾT NĂM 2017

 Yêu cầu: Các em làm bài tập vào giấy men, buổi đầu tiên đi học sau Tết nộp cho thầy

chúc các em làm hết bài tập!

Bài 1 Giaûi caùc phöông trình sau:

1. a) 3x – 2 = 2x – 3 b) 3 – 4y + 24 + 6y = y + 27 + 3y c) 7 – 2x = 22 – 3x d) 8x – 3 = 5x + 12 e) x – 12 + 4x = 25 + 2x – 1 f) x + 2x + 3x – 19 = 3x + 5 g) 11 + 8x – 3 = 5x – 3 + x h) 4 – 2x + 15 = 9x + 4 – 2x

2. a) 5 – (x – 6) = 4(3 – 2x) b) 2x(x + 2)2 – 8x2 = 2(x – 2)(x2 + 2x + 4) c) 7 – (2x + 4) = – (x + 4) d) (x – 2)3 + (3x – 1)(3x + 1) = (x + 1)3

e) (x + 1)(2x – 3) = (2x – 1)(x + 5) f) (x – 1)3 – x(x + 1)2 = 5x(2 – x) – 11(x + 2) g) (x – 1) – (2x – 1) = 9 – x h) (x – 3)(x + 4) – 2(3x – 2) = (x – 4)2

i) x(x + 3)2 – 3x = (x + 2)3 + 1 j) (x + 1)(x2 – x + 1) – 2x = x(x + 1)(x – 1)

3. a) 1,2 – (x – 0,8) = –2(0,9 + x) b) 3,6 – 0,5(2x + 1) = x – 0,25(2 – 4x) c) 2,3x – 2(0,7 + 2x) = 3,6 – 1,7x d) 0,1 – 2(0,5t – 0,1) = 2(t – 2,5) – 0,7 e) 3 + 2,25x +2,6 = 2x + 5 + 0,4x f) 5x + 3,48 – 2,35x = 5,38 – 2,9x + 10,42

4. a) b) 2

x 3 5 3

2 x 5   

9

x 8 6 1 12

3 x 10    

c) d)                 x 5 13 5 5 3 x 2 6

5,1 x 20 ) 9 x ( 5 x 8 7    

e) f) 5

x 16 x 2 6

1 x 7    

3

6 x 5 ) x 5,1 5,0 ( 4    

g) h) x 2 3 5 6

1 x 3 2

2 x 3     

2

2 x 3 x 4 x 5

4 x      

i) k) 3 3

4 x 5 7

2 x 6 5

3 x 4       5 5

2 x 4 3

1 x 8 6

2 x 5      

m) n) 15

7 x 3

2 x 5

1 x 2      ) 2 x ( 3 1 )1 x ( 2 1 3 ) 3 x ( 4 1      

p) q) x 6 x 6

1 x 2 3 x     25 ,0 4

x 2 1 x 5,0 5

x 2     

r) s) 9

3 x 5 7

5 x 3 3 x 11

11 x 3      

6

) x 2 4,0 ( 5 6

1,1 x 7 7

5,1 x 5 4

7,0 x 9       

t) u) 12

1 x 3 8

2 x 9 4

1 x 3 6

8 x 2       

12

1 x 2 3

1 x 6 3

3 x 2 4

5 x       

v) w) 30

x 15

8 x 6

3 x 2 10

1 x 5       1 x 5

2

3 x x 7

15

5

x 3 4 x 2

 

  

 

5. a) b) 5 7

)1 x 2 ( 2 4

1 x 7 6

2 )1 x ( 5       

5

) 2 x 10 ( 2 10

x 7 2 1 24 15

) 30 x ( 3 x      

c) d) 3

) 7 x ( 2 2

x 3 5

) 3 x ( 2 2 1 14      12

x 12 7 6

)1 x ( 3 x 2 4

)1 x 2 ( 3 3

1 x        

e) f) 5

) 2 x 3 ( 2 1 10

1 x 3 4

)1 x 2 ( 3      

2

3 x 10 ) x 2 1( 34

7 )1 x 2 ( 17

3 x      

g) h) 6 5

)1 x ( 3 10

5, 10 x 4 4

) 3 x ( 3      

10

2 x 3 5

)1 x 3 ( 2 5 4

1 )1 x 3 ( 2       

Bài 2 Giaûi caùc phöông trình sau: ThuVienDeThi.com

a) b) 15

5 x 14 x 7 3

)1 x ( 5

)1 x 2 ( 2 2 2      

3

) 2 x )( 10 x ( 4

) x 2 )( 4 x ( 12

) 4 x )( 10 x (        

c) 0 6

) 4 x ( 8

) 3 x 2 )( 3 x 2 ( 3

) 2 x ( 2 2

      

Bài 3 Giaûi caùc phöông trình sau:

a) b) 5

3

x 2 1 x 3 1 3

5

1 x x 2 x

   

   5

6 2

1 x 3

2

3

x 2 1 x 2

3

2

1 x 1 x 3  



  

  

Bài 4 Giaûi caùc phöông trình sau:

a) b) 27

23 x 26

23 x 25

23 x 24

23 x                                           1 95

5 x 1 96

4 x 1 97

3 x 1 98

2 x

c) d) 2001

4 x 2002

3 x 2003

2 x 2004

1 x        0 3 95 205 97 203 99 201        x x x

e) f) 47

53 x 45

55 x 53

47 x 55

45 x       

6

4 x 7

3 x 8

2 x 9

1 x       

g) h) 92

8 x 94

6 x 96

4 x 98

2 x       

2004

x 2003

x 1 1 2002

x 2     

i) 27

1973 x 10 x 29

1971 x 10 x 1973

27 x 10 x 1971

29 x 10 x 2 2 2 2           

Bài 5 Giaûi caùc phöông trình sau:

1. a) (3x – 2)(4x + 5) = 0 b) (2,3x – 6,9)(0,1x + 2) = 0 c) (4x + 2)(x2 + 1) = 0 d) (2x + 7)(x – 5)(5x + 1) = 0 e) (x – 1)(2x + 7)(x2 + 2) = 0 f) (4x – 10)(24 + 5x) = 0 g) (3,5 – 7x)(0,1x + 2,3) = 0 h) (5x + 2)(x – 7) = 0 i) 15(x + 9)(x – 3) (x + 21) = 0 j) (x2 + 1)(x2 – 4x + 4) = 0

k) (3x – 2) = 0 l) (3,3 – 11x) = 0         

5

3 x 4 7

) 3 x ( 2         

3

) 3 1( 2 5

2 7 x x

2. a) (3x + 2)(x2 – 1) = (9x2 – 4)(x + 1) b) x(x + 3)(x – 3) – (x + 2)(x2 – 2x + 4) = 0 c) 2x(x – 3) + 5(x – 3) = 0 d) (3x – 1)(x2 + 2) = (3x – 1)(7x – 10) …