`x+4/5=4/5+(3/7+3/5)`

`=> x+4/5=4/5+36/35`

`=> x+4/5= 64/35`

`=>x= 64/35 -4/5`

`=>x=  64/35 - 28/35`

`=>x= 36/35`

`----`

`5/7 + x/35 =4/5`

`=>x/35 =4/5-5/7`

`=>x/35 =28/35 - 25/35`

`=> x/35= 3/35`

`=>x=3`

\(\dfrac{5}{7}+\dfrac{x}{35}=\dfrac{4}{5}\)
\(\dfrac{x}{35}=\dfrac{4}{5}-\dfrac{5}{7}\)
\(\dfrac{x}{35}=\dfrac{28}{35}-\dfrac{25}{35}\)
\(\dfrac{x}{35}=\dfrac{3}{35}\)
\(x=3\)

nhanh lên mọi ngừi ơi , mình đang vội

75​+35x​=54​
\dfrac{x}{35}=\dfrac{4}{5}-\dfrac{5}{7}35x​=54​−75​
\dfrac{x}{35}=\dfrac{28}{35}-\dfrac{25}{35}35x​=3528​−3525​
\dfrac{x}{35}=\dfrac{3}{35}35x​=353​
$x=3$

a: =>x=3/7+3/5=15/35+21/35=36/35

b: =>x/35=4/5-5/7=28/35-25/35=3/35

=>x=3

c: =>x<3/4+8/4=11/4

=>\(x\in\left\{0;1;2;3\right\}\)

d: =>5/3<x<5/6+24/6=29/6

=>\(x\in\left\{2;3;4\right\}\)

e: =>x<10/12-9/12=1/12

=>x=0

f: =>2/3<x<12/6-5/6=7/6

=>x=1

a, ta thấy cả hai vế đều có 4/5 mà lại bằng nhau nên x bằng số hạng còn lại ở vế phải 

x=3/7+3/5

x=36/35

b,x là số hạng chưa biết nên

x=4/5-5/7

x=3/35

cảm ơn Kiều Ngọc Lan tớ đứng đầu olm lớp 4 đấy

a: =>x+7/4=6:2/3=9

=>x=29/4

b: =>x:5/3=7/5

=>x=7/5*5/3=7/3

c:=>x+1/6=5/3

=>x=10/6-1/6=3/2

d: =>x+4/5=4/5+3/7+3/5

=>x=3/7+3/5=36/35

e: =>x/35=4/5-5/7=3/35

=>x=3

f: =>13/28+x=1/2

=>x=1/28

g: =>1/3-x=1/9

=>x=2/9

Giúp

\(\dfrac{3}{7}\times x=\dfrac{1}{3}\)

\(x=\dfrac{1}{3}:\dfrac{3}{7}\)

\(x=\dfrac{7}{9}\)

\(x:\dfrac{6}{8}=\dfrac{2}{5}\)

\(x=\dfrac{2}{5}\times\dfrac{6}{8}\)

\(x=\dfrac{6}{20}=\dfrac{3}{10}\)

\(x-\dfrac{2}{3}=\dfrac{5}{6}\)

\(x=\dfrac{5}{6}+\dfrac{2}{3}\)

\(x=\dfrac{9}{6}=\dfrac{3}{2}\)

\(x-\dfrac{2}{5}-\dfrac{4}{35}=\dfrac{1}{7}\)

\(x=\dfrac{1}{7}+\dfrac{4}{35}+\dfrac{2}{5}\)

\(x=\dfrac{23}{35}\)

.

\(\dfrac{3}{7}\times x=\dfrac{1}{3}\)

\(\Leftrightarrow x=\dfrac{1}{3}:\dfrac{3}{7}\)

\(\Leftrightarrow x=\dfrac{7}{9}\)

\(x:\dfrac{6}{8}=\dfrac{2}{5}\)

\(\Leftrightarrow x=\dfrac{2}{5}\times\dfrac{6}{8}\)

\(\Leftrightarrow x=\dfrac{3}{10}\)

\(x-\dfrac{2}{3}=\dfrac{5}{6}\)

\(\Leftrightarrow x=\dfrac{5}{6}+\dfrac{2}{3}\)

\(\Leftrightarrow x=\dfrac{3}{2}\)

\(x-\dfrac{2}{5}-\dfrac{4}{35}=\dfrac{1}{7}\)

\(\Leftrightarrow x=\dfrac{1}{7}+\dfrac{2}{5}+\dfrac{4}{35}\)

\(\Leftrightarrow x=\dfrac{23}{35}\)

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 

đúng hong

a: =>5-x=-23

=>x=5+23=28

b: =>x-3-x+7-25+x=54

=>x-21=54

=>x=75

c: =>7-9x-2x+4=-5x-35+27-25=-5x-37

=>-11x+3=-5x-37

=>-6x=-40

=>x=20/3

a) \(10-x-5=\left(-5\right)-7-11\)

\(\Rightarrow5-x=-23\)

\(\Rightarrow x=5+23\)

\(\Rightarrow x=28\)

b) \(\left(x-3\right)-\left(x+17-24\right)-\left(25-x\right)=24-\left(-30\right)\)

\(\Rightarrow x-3-x-17+24-25+x=54\)

\(\Rightarrow x-21=54\)

\(\Rightarrow x=54+21\)

\(\Rightarrow x=75\)

c) \(\left(7-9x\right)-\left(2x-4\right)=-\left(5x+35\right)-\left(-27\right)-25\)

\(\Rightarrow7-9x-2x+4=-5x-35+27-25\)

\(\Rightarrow11-11x=-5x-33\)

\(\Rightarrow-11x+5x=-33-11\)

\(\Rightarrow-6x=-22\)

\(\Rightarrow x=\dfrac{22}{6}=\dfrac{11}{3}\)

a. 
10-x-5 = (-5) - 7 -11
=>5-x = 0
=>x=5
b
(x-3) - (x+17-24) - (25-x) = 24 - (-30)
=>x - 3 - x - 17 + 24 - 25 - x = 24 + 30
=>-x - 21 = 54
=>-x = 75
=>x = -75
c
(7 - 9x) - (2x - 4) = - (5x + 35) - (-27) - 25
=>7-9x - 2x + 4 = -5x - 35 + 27 - 35
=>11 - 11x + 5x = -43
=>16x = 11 + 43
=>16x = 54
=>x=4

Bài 1: 

a) Ta có: \(\dfrac{17}{6}-x\left(x-\dfrac{7}{6}\right)=\dfrac{7}{4}\)

\(\Leftrightarrow\dfrac{17}{6}-x^2+\dfrac{7}{6}x-\dfrac{7}{4}=0\)

\(\Leftrightarrow-x^2+\dfrac{7}{6}x+\dfrac{13}{12}=0\)

\(\Leftrightarrow-12x^2+14x+13=0\)

\(\Delta=14^2-4\cdot\left(-12\right)\cdot13=196+624=820\)

Vì Δ>0 nên phương trình có hai nghiệm phân biệt là:

\(\left\{{}\begin{matrix}x_1=\dfrac{14-2\sqrt{205}}{-24}=\dfrac{-7+\sqrt{205}}{12}\\x_2=\dfrac{14+2\sqrt{2015}}{-24}=\dfrac{-7-\sqrt{205}}{12}\end{matrix}\right.\)

b) Ta có: \(\dfrac{3}{35}-\left(\dfrac{3}{5}-x\right)=\dfrac{2}{7}\)

\(\Leftrightarrow\dfrac{3}{5}-x=\dfrac{3}{35}-\dfrac{10}{35}=\dfrac{-7}{35}=\dfrac{-1}{5}\)

hay \(x=\dfrac{3}{5}-\dfrac{-1}{5}=\dfrac{3}{5}+\dfrac{1}{5}=\dfrac{4}{5}\)

ai giúp mik vs

Bài 3: 

a) Ta có: \(2x-3=x+\dfrac{1}{2}\)

\(\Leftrightarrow2x-x=\dfrac{1}{2}+3\)

\(\Leftrightarrow x=\dfrac{7}{2}\)

b) Ta có: \(4x-\left(x+\dfrac{1}{2}\right)=2x-\left(\dfrac{1}{2}-5\right)\)

\(\Leftrightarrow3x-\dfrac{1}{2}-2x+\dfrac{1}{2}-5=0\)

\(\Leftrightarrow x=5\)