x = 4

\(x+\left|-3\right|=-\left|-7\right|\)

\(x+3=-7\)

\(x=-7-3\)

\(x=-10\)

\(x-\dfrac{1}{4}=\dfrac{-21}{10}\)

\(x=\dfrac{-21}{10}+\dfrac{1}{4}\)

\(x=\dfrac{-42}{20}+\dfrac{5}{20}=\dfrac{-37}{20}\)

x = 22 x 7/11

x = 14

3/2 x X = 11/2 - 7/4

3/2 x X = 22/7

X = 22/7 : 3/2

X = 44/21

a, tìm x

b, thêm ngoặc

x : 7 = 54 + 78

x      = 162 : 7 

x      = 23 

3+8 x { 4 - 2 }

=

=11 x 2 

 22

\(X:\dfrac{3}{9}=\dfrac{7}{8}\)

\(X=\dfrac{7}{8}\times\dfrac{3}{9}\)

\(X=\dfrac{21}{72}\)

\(\left(X-21\times13\right):11=30\)

\(X-273=330\)

\(X=603\)

`x:3/9=7/8`

`x=7/8xx3/9`

`x=7/24`

`-------------`

`(x-21xx13):11=30`

`(x-273):11=30`

`x-273=30xx11`

`x-273=330`

`x=330-273`

`x=57`

Bài 2: 

Ta có: \(x\left(x-4\right)-x^2+8=0\)

\(\Leftrightarrow x^2-4x-x^2+8=0\)

\(\Leftrightarrow-4x=-8\)

hay x=2

1)=x²-49-x²

=-49

2)=>x²-4x-x²+8=0

=>-4x+8=0

=>-4x=-8

=>x=2

x : 1/3 = 1/2 +1/3

=>x:1/3=5/6

=>x=5/6 x 1/3

=>x=5/18

(x:2/3):2/5=7/10

=>x:2/3=7/10 x 2/5 

=>x:2/3=7/25

=>x=7/25x2/3

=>x=14/75

CHÚC BẠN HỌC TỐT

cái này vừa gửi rồi mà:D

x:1/3=1/2+1/3
x:1/3=5/6
x      =5/6.1/3
x      =5/18
 

(x:2/3):2/5=7/10
x:2/3        =7/10.2/5
x:2/3        =7/25
x:2/3        =7/25.2/3
x:2/3        =14/75
 

x/30 + 4/5= 79/30

x/30 = 79/30 - 4/5

x/30= 11/6

11/6= 55/30

=> x= 55