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3x 8 5 6x >0 x 2 +1 x+1 >0 x 2 +1

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(1)

5.10 1)

4x 460

3x+2>0

4x64

3x> 2

x 61

x >

2

3

S= ℄ 1;1℄

\ ℄ 2

3

;+1[

=℄ 2

3

;1℄

2)

x 2

10x+2160

x 2

6x+16>0

x 2

10x+2160

x 2

+6x 16<0

(x 3)(x 7)60

(x 2)(x+8)<0

x 2 +

x+8 +

P(x) + +

x 3 + +

x 7 +

P(x) + +

8

2

0 0

0 0

3 7

0

0

0 0

S= [3;7℄

\ ℄ 8;2[

=?

3) 8

>

>

<

>

>

:

3x 8

5 6x

>0

x 2

+1

x+1

>0

x 2

+1 + +

x+1 +

F(x) +

3x 8 +

5 6x +

F(x) +

1 5

6 8

3

0

0

S= ℄ 5

6

; 8

3

\ ℄ 1;+1[

=℄ 5

6

; 8

3

4) 8

<

:

4x 460

3x+12<0

x+8>3x+2

8

<

:

4x64

3x< 12

2x> 6

(2)

<

: x61

x< 4

x<3

S= ℄ 1;1℄

\ ℄ 1; 4[

\ ℄ 1; 3[

=℄ 1; 4[

5) 3<

7 x

x+3 63

8

>

<

>

: 3<

7 x

x+3

7 x

x+3 63

8

>

<

>

: 0<

7 x

x+3 +3

7 x

x+3

360

8

>

>

<

>

>

: 0<

(7 x)+3(x+3)

x+3

(7 x) 3(x+3)

x+3

60

8

>

<

>

: 0<

2x+16

x+3

4x 2

x+3 60

4x 2 + +

x+3 + +

F(x) +

2x+16 + +

x+3 +

F(x) + +

3 1

2

0

0

8 3

0

0

S= ℄ 1; 8[[℄ 3;+1[

\ ℄ 1; 3[[[ 1

2

;+1[

=℄ 1; 8[[[ 1

2

;+1[

6) (x 2)

2x+3

2 x

4x

61

(x 2)

(2x+3) 4x(2 x)

2 x

61

(x 2) 4x

2

6x+3

2 x

61

(x 2)(4x 2

6x+3)

2 x

160

(3)

(x 2)(4x 6x+3) 1(2 x)

2 x

60

(x 2)(4x 2

6x+3)+1(x 2)

2 x

60

(x 2)(4x 2

6x+4)

2 x

60

x 2 +

4x 2

6x+4 + + =( 6)

2

444= 28<0

2 x +

F(x)

2

S=R f2g=℄ 1;2[[℄2;+1[

7)

x 2

460

3x+2>0

(x 2)(x+2)60

x >

2

3

x 2 +

x+2 + +

P(x) + +

2

2

0 0

0 0

S=[ 2;2℄\℄ 2

3

;+1[=℄ 2

3

;2℄

8) 8

<

: 4x

2

4x6 1

x+7

2

>x 3

4x 2

4x+160

x+7>2x 6

(2x 1) 2

60

13>x

S=f 1

2

g\℄ 1;13[=f 1

2 g

9) 8

>

>

<

>

>

:

3x 5

2 6x

>0

x 2

+1

(x+1) 2

>1

(4)

>

>

<

>

>

:

3x 5

2 6x

>0

x 2

+1

(x+1) 2

1>0

8

>

>

<

>

>

:

3x 5

2 6x

>0

(x 2

+1) 1(x+1) 2

(x+1) 2

>0

8

>

>

<

>

>

:

3x 5

2 6x

>0

2x

(x+1) 2

>0

2x + +

(x+1) 2

+ + +

F(x) + +

3x 5 +

2 6x +

F(x) +

1

0

0

0 1

3 5

3

0

0

S=℄ 1

3

; 5

3

℄ \ ℄ 1; 1[[℄ 1;0[

=?

10) 3<1 x 2

63

3<1 x 2

1 x

2

63

0<4 x 2

06x 2

+2

0<(2 x)(2+x)

06x 2

+2

x 2

+2 + =0 2

412= 8<0

2 x + +

2+x + +

P(x) +

2

2

0 0

0 0

S=℄ 2;2[\R =℄ 2;2[

11) 8

<

:

9x 2<3x 14

5x+3<15 7x

11x 4>10x 9

8

<

:

6x< 12

12x<12

x> 5

(5)

<

:

x< 2

x<1

x> 5

S= ℄ 1; 2[

\ ℄ 1;1[

\ ℄ 5;+1[

=℄ 5; 2[

12) 8

>

>

<

>

>

:

4x 5

2 3x

>0

x 2

+4

x+2

>0

x 2

+4 + +

x+2 +

F(x) +

4x 5 +

2 3x +

F(x) +

2 2

3 5

4

0

0

S= ℄ 2

3

; 5

4

\ ℄ 2;+1[

=℄ 2

3

; 5

4

13) 8

>

>

>

>

>

<

>

>

>

>

>

:

(x+1) 3

3(x 1) 2

>x 3

11

3x 1

2

<x+

x 2

5

1+ 2

x 6

3

x 2

8

>

>

<

>

>

: x

3

+3x 2

+3x+1 3x 2

+6x 3>x 3

11

5(3x 1)<10x+2(x 2)

061+ 2

x +

3

x 2

8

>

>

<

>

>

: x

3

+9x 2>x 3

11

15x 5<10x+2x 4

06 x

2

+2x+3

x 2

8

>

>

<

>

>

:

9x> 9

3x<1

06 x

2

+2x+3

x 2

8

>

>

<

>

>

:

x> 1

x<

1

3

06 x

2

+2x+3

x 2

(6)

x 2

+2x+3 + + =2

2

413= 8<0

x 2

+ +

F(x) + +

S= ℄ 1;+1[

\ ℄ 1; 1

3 [

\ R f0g

=℄ 1;0[[℄0; 1

3 [

14) 8

>

>

<

>

>

:

(x+2)(6 x)>0

x 2

x 1260

x

x 2

9

>0

8

>

>

<

>

>

:

(x+2)(6 x)>0

(x 4)(x+3)60

x

(x 3)(x+3)

>0

x 4 +

x+3 + +

P(x) + +

x+2 + +

6 x + +

P(x) +

3

4

0 0

0 0

2

6

0

0

0 0

x + +

x 3 +

x+3 + + +

F(x) + +

3

0 3

0

0

S= [ 2;6℄

\ [ 3;4℄

\ ℄ 3;0[[℄3;+1[

=[ 2;0[[℄3;4℄

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