1).( 27,56 x 35 ) + ( 27,56 x 67 ) - ( 27,56 x 2)

= (964 + 1846,52) - 55,12

=2810,52 - 55,12

= 2755,4

2).( 4x 35 ) x ( 25 x 5 ) x 2

= ( 140 x 125 ) x2

= 17500 x 2

=35000

4). 3/10

5). 1188

6).  61/6

1)2756   2)35000   3)0   4)3/10   5)10/1/6

d) 3 -x = |-4|

3-x=4

x=-1

e) 35 - |2 x+1|=14

|2 x+1|=21

\(\Leftrightarrow\orbr{\begin{cases}2x+1=21\\2x+1=-21\end{cases}\Leftrightarrow\orbr{\begin{cases}x=10\\x=-11\end{cases}}}\)

f) |x| -3 +6 =16

|x|=13

\(x=\pm13\)

P/s tham khảo nha

d)=>3-x=4

=>x=3-4

=>x=-1

vậy x=-1

e)=>l2x+1l=35-14=21

=>\(\orbr{\begin{cases}2x+1=21\\2x+1=-21\end{cases}\Leftrightarrow\orbr{\begin{cases}2x=21-1=20\\2x=-21-1=-22\end{cases}\Leftrightarrow\orbr{\begin{cases}x=20:2=10\\x=-22:2=-11\end{cases}}}.}\)

vậy x=10,x=-11

f)=>lxl=16-6+3=13

\(\Rightarrow x=\pm13\)

vậy..............

a ) |x| + 28 = 35 \(\Rightarrow\) |x| = 35 - 28 = 7

                          \(\Rightarrow\)x = 7 hoặc x = - 7

b ) |x| + 29 = 15 \(\Rightarrow\)|x| = 15 - 29 = - 6 

                           \(\Rightarrow\)x = -7

c ) |x-1| = 0  \(\Rightarrow\)x - 1 = 0

                     \(\Rightarrow\)x = 1

d ) 2 x | x+2 | = 16 \(\Rightarrow\)| x+2 | = 16 : 2 = 8

                               \(\Rightarrow\)x + 2 = 8           hoặc          x + 2 = - 8

                                              x  = 8 -2                            x    = - 8 - 2

                                              x   = 6                                x    = -10

e ) 3 x | x-1 | = 12 - 3 

     3 x | x-1 |  = 9   

           | x-1 |  = 9 : 3

            | x-1 | = 3  \(\Rightarrow\)x - 1 = 3            hoặc           x - 1 = - 3

                                          x   = 3 + 1                             x  = - 3 + 1

                                           x   = 4                                    x = -2

dài quá à :(

1) x - 43 = (35 - x) - 48

=> x + x = 35 - 48 + 43

=> x + x = 30

=> x = 30 : 2

=> x = 15

2) 305 - x + 14 = 48 + (x + 23)

=> 305 - x + 14 = 48 + x + 23

=> -x - x = 48 + 23 - 14 - 305

=> -x - x = -248

=> -x = -248 : 2

=> -x = -124

=> x = 124

3) - (x - 6 + 85) = (x + 51) - 54

=> -x + 6 - 85 = x + 51 - 54

=> -x - x = 51 - 54 + 85 - 6

=> -x - x = 76

=> -x = 76 : 2

=> -x = 38

=> x = -38

4) - (35 - x - 37 - x) = 33 - x

=> -35 + x + 37 + x = 33 - x

=> x + x + x = 33 + 35 - 37

=> x + x + x = 31

=> x = 31 : 3

=> x \(=\dfrac{31}{3}\)

Vì x \(\in\) Z nên không có giá trị x nào thỏa mãn trong câu này.

5) 13 - | x | = | -4 |

=> 13 - |x| = 4

=> |x| = 13 - 4

=> |x| = 9

=> \(\left[{}\begin{matrix}x=9\\x=-9\end{matrix}\right.\)

6) | x | - 3 + 6 = 16

=> |x| = 16 - 6 + 3

=> |x| = 13

=> \(\left[{}\begin{matrix}x=13\\x=-13\end{matrix}\right.\)

7) 35 - | 2x - 1 | = 14

=> |2x - 1| = 35 - 14

=> |2x - 1| = 21

=> \(\left[{}\begin{matrix}2x-1=21\\2x-1=-21\end{matrix}\right.=>\left[{}\begin{matrix}2x=21+1\\2x=-21+1\end{matrix}\right.=>\left[{}\begin{matrix}2x=22\\2x=-20\end{matrix}\right.=>\left[{}\begin{matrix}x=22:2\\x=-20:2\end{matrix}\right.=>\left[{}\begin{matrix}x=11\\x=-10\end{matrix}\right.\)

8) | 3x - 2 | + 5 = 9 - x

=> |3x - 2| = 9 - 5 - x

=> |3x - 2| = 4 - x

=> \(\left[{}\begin{matrix}3x-2=4-x\\3x-2=x-4\end{matrix}\right.=>\left[{}\begin{matrix}3x+x=4+2\\3x-x=-4+2\end{matrix}\right.=>\left[{}\begin{matrix}4x=6\\2x=-2\end{matrix}\right.=>\left[{}\begin{matrix}x=6:4\\x=-2:2\end{matrix}\right.=>\left[{}\begin{matrix}x=\dfrac{6}{4}\\x=-1\end{matrix}\right.\)

Vì x \(\in\) Z nên x = -1.

9) x - ( -25 + 7 ) > 12 - ( 15 - 14 )

=> x - (-18) > 12 - 1

=> x + 18 > 11

=> x > 11 - 18

=> x > -7

10) | 17 + ( x - 15 ) | < 4

=> \(\left[{}\begin{matrix}17+\left(x-15\right)< 4\\17+\left(x-15\right)< -4\end{matrix}\right.=>\left[{}\begin{matrix}x-15< 4-17\\x-15< -4-17\end{matrix}\right.=>\left[{}\begin{matrix}x-15< -15\\x-15< -21\end{matrix}\right.=>\left[{}\begin{matrix}x< -15+15\\x< -21+15\end{matrix}\right.=>\left[{}\begin{matrix}x< 0\\x< -6\end{matrix}\right.=>x< -6\)

11) x2 - 5x = 0

=> x . (2 - 5) = 0

=> x . (-3) = 0

=> x = 0 : (-3)

=> x = 0

12) | x-9 | . (-8) = -16

=> |x - 9| = (-16) : (-8)

=> |x - 9| = 3

=> \(\left[{}\begin{matrix}x-9=3\\x-9=-3\end{matrix}\right.=>\left[{}\begin{matrix}x=3+9\\x=-3+9\end{matrix}\right.=>\left[{}\begin{matrix}x=12\\x=6\end{matrix}\right.\)

13) | 4 - 5x | = 24 với x < hoặc = 0

=> \(\left[{}\begin{matrix}4-5x=24\\4-5x=-24\end{matrix}\right.=>\left[{}\begin{matrix}5x=4-24\\5x=4-\left(-24\right)\end{matrix}\right.=>\left[{}\begin{matrix}5x=-20\\5x=28\end{matrix}\right.=>\left[{}\begin{matrix}x=-20:5\\x=28:5\end{matrix}\right.=>\left[{}\begin{matrix}x=-4\\x=\dfrac{28}{5}\end{matrix}\right.\)

Vì x \(\le\) 0 nên x = -4

14) x . ( x - 2 ) > 0

=> \(\left[{}\begin{matrix}\left\{{}\begin{matrix}x>0\\x-2>0\end{matrix}\right.\\\left\{{}\begin{matrix}x< 0\\x-2< 0\end{matrix}\right.\end{matrix}\right.=>\left[{}\begin{matrix}\left\{{}\begin{matrix}x>0\\x>2\end{matrix}\right.\\\left\{{}\begin{matrix}x< 0\\x< 2\end{matrix}\right.\end{matrix}\right.=>\left[{}\begin{matrix}x>2\\x< 2\end{matrix}\right.\)

15) x . ( x - 2 ) < 0

=> \(\left[{}\begin{matrix}\left\{{}\begin{matrix}x< 0\\x-2>0\end{matrix}\right.\\\left\{{}\begin{matrix}x>0\\x-2< 0\end{matrix}\right.\end{matrix}\right.=>\left[{}\begin{matrix}\left\{{}\begin{matrix}x< 0\\x>2\end{matrix}\right.\\\left\{{}\begin{matrix}x>0\\x< 2\end{matrix}\right.\end{matrix}\right.=>\left[{}\begin{matrix}2>x< 0\left(loại\right)\\0< x< 2\left(chọn\right)\end{matrix}\right.=>0< x< 2\)

16) (x-1) . (y+1) = 5

=> \(\left[{}\begin{matrix}x-1=5\\y+1=1\end{matrix}\right.=>\left[{}\begin{matrix}x=5+1\\y=1-1\end{matrix}\right.=>\left[{}\begin{matrix}x=6\\y=0\end{matrix}\right.\)

hoặc

=> \(\left[{}\begin{matrix}x-1=1\\y+1=5\end{matrix}\right.=>\left[{}\begin{matrix}x=1+1\\y=5-1\end{matrix}\right.=>\left[{}\begin{matrix}x=2\\y=4\end{matrix}\right.\)

hoặc

=> \(\left[{}\begin{matrix}x-1=-1\\y+1=-5\end{matrix}\right.=>\left[{}\begin{matrix}x=-1+1\\y=-5-1\end{matrix}\right.=>\left[{}\begin{matrix}x=0\\y=-6\end{matrix}\right.\)

hoặc

=> \(\left[{}\begin{matrix}x-1=-5\\y+1=-1\end{matrix}\right.=>\left[{}\begin{matrix}x=-5+1\\y=-1-1\end{matrix}\right.=>\left[{}\begin{matrix}x=-4\\y=-2\end{matrix}\right.\)

17) x . ( y +2 ) = -8

=> \(\left[{}\begin{matrix}x=1\\y+2=-8\end{matrix}\right.=>\left[{}\begin{matrix}x=1\\y=-8-2\end{matrix}\right.=>\left[{}\begin{matrix}x=1\\y=-10\end{matrix}\right.\)

hoặc

=> \(\left[{}\begin{matrix}x=-1\\y+2=8\end{matrix}\right.=>\left[{}\begin{matrix}x=-1\\y=8-2\end{matrix}\right.=>\left[{}\begin{matrix}x=-1\\y=4\end{matrix}\right.\)

hoặc

=> \(\left[{}\begin{matrix}x=-8\\y+2=1\end{matrix}\right.=>\left[{}\begin{matrix}x=-8\\y=1-2\end{matrix}\right.=>\left[{}\begin{matrix}x=-8\\y=-1\end{matrix}\right.\)

hoặc

=> \(\left[{}\begin{matrix}x=8\\y+2=-1\end{matrix}\right.=>\left[{}\begin{matrix}x=8\\y=-1-2\end{matrix}\right.=>\left[{}\begin{matrix}x=8\\y=-3\end{matrix}\right.\)

hoặc

=> \(\left[{}\begin{matrix}x=2\\y+2=-4\end{matrix}\right.=>\left[{}\begin{matrix}x=2\\y=-4-2\end{matrix}\right.=>\left[{}\begin{matrix}x=2\\y=-6\end{matrix}\right.\)

hoặc

=> \(\left[{}\begin{matrix}x=-2\\y+2=4\end{matrix}\right.=>\left[{}\begin{matrix}x=-2\\y=4-2\end{matrix}\right.=>\left[{}\begin{matrix}x=-2\\y=2\end{matrix}\right.\)

hoặc

=> \(\left[{}\begin{matrix}x=4\\y+2=-4\end{matrix}\right.=>\left[{}\begin{matrix}x=4\\y=-4-2\end{matrix}\right.=>\left[{}\begin{matrix}x=4\\y=-6\end{matrix}\right.\)

hoặc

=> \(\left[{}\begin{matrix}x=-4\\y+2=2\end{matrix}\right.=>\left[{}\begin{matrix}x=-4\\y=2-2\end{matrix}\right.=>\left[{}\begin{matrix}x=-4\\y=0\end{matrix}\right.\)

18) xy - 2x - 2y = 0

=> x . (y - 2) - 2y = 0

=> x . (y - 2) - 2y - 4 = -4

=> x . (y - 2) - 2 . (y - 2) = -4

=> (y - 2) . (x - 2) = -4

=> \(\left[{}\begin{matrix}y-2=1\\x-2=-4\end{matrix}\right.=>\left[{}\begin{matrix}y=1+2\\x=-4+2\end{matrix}\right.=>\left[{}\begin{matrix}y=3\\x=-2\end{matrix}\right.\)

hoặc

=> \(\left[{}\begin{matrix}y-2=-1\\x-2=4\end{matrix}\right.=>\left[{}\begin{matrix}y=-1+2\\x=4+2\end{matrix}\right.=>\left[{}\begin{matrix}y=1\\x=6\end{matrix}\right.\)

hoặc

=> \(\left[{}\begin{matrix}y-2=2\\x-2=-2\end{matrix}\right.=>\left[{}\begin{matrix}y=2+2\\x=-2+2\end{matrix}\right.=>\left[{}\begin{matrix}y=4\\x=0\end{matrix}\right.\)

hoặc

=> \(\left[{}\begin{matrix}y-2=-2\\x-2=2\end{matrix}\right.=>\left[{}\begin{matrix}y=-2+2\\x=2+2\end{matrix}\right.=>\left[{}\begin{matrix}y=0\\x=4\end{matrix}\right.\)

19) 2x - 5 \(⋮\) x - 1

=> (2x - 2) - (5 - 2) \(⋮\) x - 1

=> 2(x - 1) - 3 \(⋮\) x - 1

Vì 2(x - 1) \(⋮\) x - 1 nên 3 \(⋮\) x - 1

=> x - 1 \(\in\) Ư(3) = {-3; -1; 1; 3}

=> x \(\in\) {-2; 0; 2; 4}

P/s: Mình không bảo đảm là đúng hết nên câu nào sai thì bạn thông cảm nha~

a. (5.x + 3) : 4 – 16 = 6

(5.x + 3) : 4  = 22 

(5.x + 3)  = 88 

5.x  = 85

x = 13

b. 7(23 – 3.x) : 2 – 35 = 35

 7(23 – 3.x) : 2 = 70 

7(23 – 3.x) = 35 

 7 . 3.x = 12

7.x = 4 

x = 4/7 

a.) (5.x + 3) : 4 – 16 = 6

=> (5.x + 3) : 4  = 22

=> 5.x + 3  = 88

=>   5x  = 85 

=>   x  =  17

b) 7(23 – 3.x) : 2 – 35 = 35

=>  7(23 – 3.x) : 2  = 70

=>7(23 – 3.x)  = 140

=>   23 – 3.x  =  20

=>    3x    =  3 

=>   x  =  1 

1/ Ta có : ( -16 ) + 23 + x = ( -16 )

 <=> 23 + x                        = ( -16 ) + 16 

<=> 23 + x                            = 0

<=> x                                      = 0 -23

<=> x                                    = -23

Vậy x = -23

2/ Ta có : 2.x - 35 = 15

<=> 2.x                    = 15 + 35

<=>    2.x                  = 50

<=> x                         = 50 : 2

<=> x                        = 25

Vậy x = 25

1/    -16 + 23 + x = -16 

[(-16) +23] +x = -16

7 + x = -16

x= -16 - 7 

x= -23

2/   2x - 35 = 15

2x= 15 + 35

2x = 50

x= 50:2

x= 25

Chúc bạn làm bài tốt

1) 15:(x+2) = 3

x + 2 = 15 : 3

x + 2 = 5

x = 5 - 2

x = 3

2) 20:(1+x) = 2

1 + x = 20 : 2

1 + x = 10

x = 10 - 1

x = 9

3) 5(x+35) = 515

x + 35 = 515 : 5

x + 35 = 103

x = 103 - 35

x = 68

4) 541+(218-x) = 73

218 - x = 73 - 541

218 - x = -468

x = 218 - ( - 468 )

x = 686

5) 1230:3 (x-20) = 10

410 . ( x - 20 ) = 10

x - 20 = 10 : 410

x - 20 = 1/41

x = 1/41 + 20

x = 821/41

6) 48-3(x+5) = 24

3( x + 5 ) = 48 - 24

3( x + 5 ) = 24

x + 5 = 24 : 3

x + 5 = 8

x = 8 - 5

x = 3

7) 4x + 18 : 2=13

4x + 9 = 13

4x = 13 - 9

4x = 4

x = 1

8) X-48:16 = 37

x - 3 = 37

x = 37 + 3

x = 40

a, 15: (x+2) = 3

x+2 =15:3

x+2 = 5

x = 5-2

x = 3

b, 20: (1+x) = 2

1+x = 20:2

1+x = 10

x = 10-1

x = 9

c, 5(x+35) = 515

x+35 = 515 :5

x+35 = 103

x = 103-35

x = 68

d, 541+ (218-x) = 73

218-x = 73-541

218-x = - 468

x = 218 - (-468)

x = 218 + 468

x = 686

e, 1230:3. (x-20) = 10

410(x-20) = 10

x-20 = 10: 410

x-20 = 1/41

x = 1/41 + 20

x = 821/41

f, 48-3(x+5) = 24

3(x+5) = 48-24

3(x+5) = 24

x+5 = 24:3

x +5 = 8

x = 8-5

x =3

g, 4x + 18 : 2 = 13

4x + 9 = 13

4x = 13-9

4x = 4

x = 4:4

x = 1

j, x - 48:16 = 37

x- 3 = 37

x = 37+3

x = 40