`a)(4,5-2x)*1 4/7=11/14`

`=>(4,5-2x)*11/7=11/14`

`=>4,5-2x=1/2`

`=>2x=4,5-0,5=4`

`=>x=2`

Vậy `x=2`

`b)(2,8x-32):2/3=-90`

`=>2,8x-32=-90*2/3=-60`

`=>2,8x=-28`

`=>x=-10`

Vậy `x=-10`

d: =>-x-5/6=7/12-4/12=3/12=1/4

=>-x=1/4+5/6=13/12

hay x=-13/12

e: =>x+3=-5

hay x=-8

f: =>4,5-2x=-1/2

=>2x=5

hay x=5/2

tham khảo

cái này đúng không nhỉ 

\(\Leftrightarrow4,5-2x=\dfrac{11}{14}:\dfrac{11}{7}\)

\(\Leftrightarrow4,5-2x=\dfrac{1}{2}\)

\(\Leftrightarrow2x=4,5-\dfrac{1}{2}\)

\(\Leftrightarrow x=4:2\)

\(\Leftrightarrow x=2\)

4,5 -2x = 11/14 : 1 4/7

4,5 -2x = 11/14 : 11/7

4,5 -2x =  1/2

2x = 4,5 - 1/2

2x = 4

x = 4 : 2

x = 2

a: =>x-3/4=1/6-1/2=1/6-3/6=-2/6=-1/3

=>x=-1/3+3/4=-4/12+9/12=5/12

b: =>x(1/2-5/6)=7/2

=>-1/3x=7/2

hay x=-21/2

c: (4-x)(3x+5)=0

=>4-x=0 hoặc 3x+5=0

=>x=4 hoặc x=-5/3

d: x/16=50/32

=>x/16=25/16

hay x=25

e: =>2x-3=-1/4-3/2=-1/4-6/4=-7/4

=>2x=-7/4+3=5/4

hay x=5/8

(4,5 - 2\(x\)) (-1\(\dfrac{4}{7}\)) = \(\dfrac{11}{14}\)

(4,5 - 2\(x\)) (-\(\dfrac{11}{7}\)) = \(\dfrac{11}{14}\)

4,5 - 2\(x\) = \(\dfrac{11}{14}\) : ( - \(\dfrac{11}{7}\))

4,5 - 2\(x\) = \(\dfrac{11}{14}\) \(\times\) (- \(\dfrac{7}{11}\))

4,5 - 2\(x\) = - \(\dfrac{1}{2}\) 

4,5 - 2\(x\) = -0,5

2\(x\) = 4,5 + 0,5

2\(x\) = 5

\(x\) = 5: 2

\(x\) = 2,5 

\(\left(2,8x-32\right)\div\frac{2}{3}=-90\)

\(\Rightarrow2,8x-32=-60\)

\(\Rightarrow2,8x=-28\)

\(\Rightarrow x=-10\)

\(\left(4,5-2x\right)\times1\frac{4}{7}=\frac{11}{14}\)

\(\Rightarrow4,5-2x=\frac{1}{2}\)

\(\Rightarrow2x=4\)

\(\Rightarrow x=2\)

`a)4/5+5 1/2 xx (4,5-2)+7/10`

`=4/5+11/2*2,5+7/10`

`=0,8+2,2+0,7`

`=3+0,7=3,7`

`b)125%xx 17/4:(1 5/16-0,5)+2008`

`=1,25xx4,25:13/16+2008`

`=85/13+2008`

`=2014 7/13`

`c)5/11+(16/11+1)`

`=5/11+1+5/11+1`

`=2+10/11=32/11`

`d)3/17+11/4+5/8+14/17+3/8`

`=3/17+14/17+5/8+3/8+11/4`

`=1+1+11/4`

`=19/4`

a) 

\(\dfrac{4}{5}+5\dfrac{1}{2}x\left(4,5-2\right)=\dfrac{7}{10}\)

<=> \(\dfrac{11}{2}x\times2,5=\dfrac{7}{10}-\dfrac{4}{5}=\dfrac{-1}{10}\)

<=> \(\dfrac{55}{4}x=\dfrac{-1}{10}< =>x=\dfrac{-2}{275}\)

b) \(125\%\times\dfrac{17}{4}:\left(1\dfrac{5}{16}-0,5\right)+2008\)

= \(\dfrac{85}{16}:\left(\dfrac{21}{16}-\dfrac{1}{2}\right)+2008=\dfrac{85}{16}:\dfrac{13}{16}+2008=\dfrac{26189}{13}\)

c) \(\dfrac{5}{11}+\left(\dfrac{16}{11}+1\right)\)

= \(\dfrac{21}{11}+1=\dfrac{32}{11}\)

d) \(\left(\dfrac{3}{17}+\dfrac{14}{17}\right)+\left(\dfrac{5}{8}+\dfrac{3}{8}\right)+\dfrac{11}{4}\)

= 1 + 1 + \(\dfrac{11}{4}\) = \(\dfrac{19}{4}\)

=>4,5-2x=11/14:11/7=1/2

=>2x=4

hay x=2

\(\left(4,5-2x\right)\cdot1\dfrac{4}{7}=\dfrac{11}{14}\)

\(\left(\dfrac{9}{2}-2x\right)\cdot\dfrac{11}{7}=\dfrac{11}{14}\)

\(\dfrac{9}{2}-2x=\dfrac{11}{14}:\dfrac{11}{7}\)

\(\dfrac{9}{2}-2x=\dfrac{1}{2}\)

\(2x=\dfrac{9}{2}-\dfrac{1}{2}\)

\(2x=\dfrac{8}{2}\)

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

`x=2`

|2x-1|=1,5

TH(1)2x-1=1,5

2x =1,5+1

2x =2,5

x =2,5 :2

x =1,25

TH(2) 2x-1=-1,5

2x =-1,5+1

2x =-0,5

x =-0,5:2

x =-0,25

các câu khác cứ tương tự bạn nhé

b) \(7,5-\left|5-2x\right|=-4,5\)

\(\left|5-2x\right|=7,5+4,7\)

\(\left|5-2x\right|=12\)

th1 :\(5-2x=12\)

\(2x=5-12\)

\(2x=-7\)

\(x=-7:2\)

\(x=-3,5\)

th2: \(5-2x=-12\)

\(2x=5+12\)

\(2x=17\)

\(x=17:2\)

\(x=8,5\)

c) \(-3+\left|x\right|=-1\)

\(\left|x\right|=-1+3\)

\(\left|x\right|=2\)

th1: \(x=-2\)

th2 : \(x=2\)

d)\(\left|2\dfrac{1}{3}-x\right|=\dfrac{1}{6}\)

\(\left|\dfrac{7}{3}-x\right|=\dfrac{1}{6}\)

th1 :\(\dfrac{7}{3}-x=\dfrac{1}{6}\)

\(x=\dfrac{7}{3}-\dfrac{1}{2}\)

\(x=\dfrac{11}{6}\)

th2: \(\dfrac{7}{3}-x=\dfrac{-1}{6}\)

\(x=\dfrac{7}{3}+\dfrac{1}{6}\)

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

e) \(\dfrac{5}{7}-\left|x+1\right|=\dfrac{1}{14}\)

\(\left|x+1\right|=\dfrac{5}{7}-\dfrac{1}{14}\)

\(\left|x+1\right|=\dfrac{9}{14}\)

th1 :\(x+1=\dfrac{9}{14}\)

\(x=\dfrac{9}{14}-1\)

\(x=\dfrac{-5}{14}\)

th2 : \(x+1=\dfrac{-9}{14}\)

\(x=\dfrac{-9}{14}-1\)

\(x=\dfrac{-5}{14}\)