1 , 10

2 , 8

3 , 5

4 , 2

5 , 1

6 ,

1/ `|x|=10<=> x=\pm 10`

2/ `|x-8|=0<=>x-8=0<=>x=8`

3/ `7+|x|=12<=>|x|=5<=>x=\pm 5`

4/ `|x+1|=3`

$\Leftrightarrow\left[\begin{array}{1}x+1=3\\x+1=-3\end{array}\right.\\\Leftrightarrow\left[\begin{array}{1}x=3\\x=-4\end{array}\right.$

5/ `15-x=16-(14-42)`

`<=>15-x=16+28`

`<=>15-x=44`

`<=>x=-29`

6/ `210-(x-12)=168`

`<=>210-x+12=168`

`<=>222-x=168`

`<=>x=54`

1.

\(\left|x\right|=10\Leftrightarrow x=\pm10\)

2.

\(\left|x-8\right|=0\Leftrightarrow x-8=0\Leftrightarrow x=8\)

3.

\(7+\left|x\right|=12\Leftrightarrow\left|x\right|=5\Leftrightarrow x=\pm5\)

[ ( 6x - 39 ) : 7 ] . 4 = 12

=> ( 6x - 39 ) : 7 = 12 : 4

=> ( 6x - 39 ) : 7 = 3

=> 6x - 39 = 3.7

=> 6x - 39 = 21

=> 6x = 21+39

=> 6x = 60

=> x = 10.

( x : 3 - 4 ) . 5 = 15

=> x : 3 - 4 = 15 : 5

=> x : 3 - 4 = 3

=> x : 3 = 7

=> x = 7.3

=> x = 21

x - [ 42 + (-28) ] = -8

=> x - 14 = -8

=> x = -8 + 14

=> x = 6.

[ (6x - 39): 7] . 4=12

(6x-39) : 7=12:4

(6x -39) :7=3

(6x-39) =3 . 7

6x-39 =21

6x =21 +39

6x=20

x=10

(x :3 -4) .5 =15

(x : 3 -4) =15:5

x:3-4 =3

x : 3=3+4

x:3 =7

x=7 . 3

x=21

a)=>x=13+3/5=68/5.

Vậy x = 68/5

b)=>x/6=5/7+-23/42

=>x/6=1/6

=>x=1

Vậy x=1

còn lại tự làm nha😆😆😆😆😆

a) x-3/5=13

suy ra x=13+3/5

suy ra x=68/5

suy ra x=13.6

b)x/6=5/7+23/-42

suy ra x/6=1/6

suy ra x=1

d) x+11/12=2/5

suy ra x=2/5-11/12

suy ra x=-31/60

BT1 :thực hành phép tính

4/3+-11/31+3/10-20/31-2/5 = 7/30

7/12-1/-16+3/4 = 67/48

2/11.-5/4+-9/11.5/4+ 1 và 3/4 = -1/4 * và 3/4 là sao bạn *

-9/27-25/75 = -2/3

tick rồi trả lời cho

a) 12 : x = 3

     X = 12 : 3

     X = 4

b) 21 : x = 7

     X = 21 : 7

     X = 3

c) 30 : x = 3

     X = 30 : 3

     X = 10

d) X : 7 = 4

     X = 4 x 7

     X = 28

e) 20 : x = 5

     X = 20 : 5

     X = 4

f) X x 6 = 42

     X = 42 : 6

     X = 7

a.-1,75-(-\(\dfrac{1}{9}\)-2\(\dfrac{1}{8}\))
-1,75-\(\dfrac{1}{9}+\dfrac{17}{8}\)
\(-\dfrac{7}{4}-\dfrac{1}{9}+\dfrac{17}{8}\)
\(\dfrac{-126}{72}-\dfrac{8}{72}+\dfrac{153}{72}\)
=\(\dfrac{19}{72}\)

b.\(\dfrac{-1}{12}-\left(2\dfrac{5}{8}-\dfrac{1}{3}\right)\)
\(\dfrac{-1}{12}-\left(\dfrac{21}{8}-\dfrac{1}{3}\right)\)
\(\dfrac{-1}{12}-\dfrac{21}{8}+\dfrac{1}{3}\)
\(\dfrac{-2}{24}-\dfrac{63}{24}+\dfrac{64}{24}\)
=\(\dfrac{-1}{24}\)

\(\dfrac{-5}{6}-\left(\dfrac{-3}{8}+\dfrac{1}{10}\right)\)
\(\dfrac{-5}{6}-\dfrac{-3}{8}-\dfrac{1}{10}\)
 

b: \(\Leftrightarrow25-x=30\)

hay x=-5

bài 1

A)37/60

B)13/45

C)1/4

bài 2

a)42/25:y/5=5/6

y=10,08

b)27/y:9/4=3/7

y=28