A = 3469 - 54 / 6038 - 108

A = 3469 - 54 / 3469 x2 - 54x2

A= 1/2

B = 2468 -98 / 3702 -147

B =2x1234 - 2x49 / 2x1234 - 3x49

B = 2/3

a, x + 26 = 39 + (-5)

   x + 26 = 39 - 5

   x + 26 = 34

   x        = 34 - 26

   x        = 8

b, |x| + 50 = (-|-26|) +76

    |x| +50 = (-26) +76

    |x| +50 = 76 - 26

    |x| +50 = 50

    |x|        = 50 -50

    |x|        = 0

c, |x| + 17 = (-21)+19

    |x| + 17 = - (21-19)

    |x| + 17 = - 2

    |x| không tồn tại

d. |x-21|= 2.(|-11| + |-3|)

    |x-21|= 2.(11+3)

    |x-21|= 2.14

    |x-21|= 28

     x     = 28+21 hoặc 21-28

     x     = 49      hoặc -7

e. hình như lộn đề vì |x-54|-7|

a) 2x -18 = 10

    =>2x = 28

    => x = 14

b) 3x + 26 = 5

=> 3x = -21

=> x = -7

Ai làm cả 2 bài mình tích

a, 568 + 568 x 135 - 568 x 36

= 568 x ( 1 + 135 - 36)

= 568 x 100

56 800

b, 17 x 49 + 49 x 37 + 54 x 26 + 54 x 25

=  49 x ( 17 + 37) + 54 x ( 26 + 25 )

= 49 x 54 + 54 x 51

= 54 x ( 49 + 51)

= 54 x 100

= 5 400

c,   14 x 35 x 5 + 10 x 25 x 7 + 20 x 70

 =    ( 2 x 35) x ( 7 x 5)  + ( 10 x 7) x 25 + 20 x 70

= 70 x 35 + 70 x 25 + 20 x 70

= 70 x ( 35 + 25 + 20)

= 70 x 80

= 5 600 

a) 568 + 568 x 135 - 568 x 36

= 568 x ( 1+1+135-1-36 )

=568 x 100

=5680

b) 17 x 49 + 49 x 37 + 54 x 26 + 54 x 25

= 49 x ( 17 + 37 ) + 54 x ( 26 + 25 )

= 49 x 54 + 54 x 51

= 54 x ( 49 + 51 )

= 54 x 100

= 5400

c) 14 x 35 x 5 + 10 x 25 x 7 + 20 x 70

= 70 x 35 + 10 x 25 x 7+ 20 x 70

= 70 x 35 + 250 x 7 + 20 x 70

= 70 x 35 + 70 x 25 + 20 x 70

= 70 x (35+25+20)

= 70 x 80

= 5600

Bài 1: 

\(=\dfrac{-3-39}{42}+\dfrac{-6-11}{17}-\dfrac{1}{6}=-\dfrac{119}{48}\)

Bài 2: 

=>x:5=-13/20

hay x=-65/20=-13/4

Bài 6:

\(21,251+6,058+0,749+1,042\)

\(=\left(21,251+0,749\right)+\left(6,058+1,042\right)\)

\(=22+7,1\)

\(=29,1\)

___________________

\(1,53+5,309+12,47+5,691\)

\(=\left(1,53+12,47\right)+\left(5,309+5,691\right)\)

\(=14+11\)

\(=25\)

5:

a: =>x/17=5/17

=>x=5

b; =>6+x=7/11*33=21

=>x=15

c: \(\dfrac{12+x}{43-x}=\dfrac{2}{3}\)

=>3x+36=86-2x

=>5x=50

=>x=10

d: \(\dfrac{x}{5}< \dfrac{3}{7}\)

=>x<3/7*5

=>x<15/7

f: 15/26+x/16=46/52

=>x/16=23/26-15/26=8/26=4/13

=>x=4/13*16=64/13

Bài 1: 

\(=\dfrac{-3-39}{32}+\dfrac{-6-11}{17}+\dfrac{-1}{6}=-\dfrac{21}{16}+\dfrac{-1}{6}-1=-\dfrac{119}{48}\)

Bài 2: 

\(\Leftrightarrow x:5=-\dfrac{13}{20}\)

hay x=-13/4

⇔x:5=−1320⇔x:5=−1320

hay x=-13/4