em ko giai duoc ,em lop 2

-3/2 - | 3x + 4 |.2/5= 2

<=> | 3x + 4 | = (2+3/2)/(2/5)

<=>  | 3x + 4 | = 35/4

<=>3x + 4 =35/4

Hoặc 3x + 4 = - 35/4

Tự giải nốt nha

\(|3x+4|.\frac{2}{5}=\frac{-3}{2}-2\)

\(|3x+4|.\frac{2}{5}=\frac{-7}{2}\)

\(|3x+4|=\frac{-7}{2}:\frac{2}{5}\)

\(|3x+4|=\frac{-35}{4}\)

\(\Leftrightarrow3x+4=\frac{-35}{4}\)        hoặc          \(3x+4=\frac{35}{4}\)

         x=\(\frac{-17}{4}\)                                                x=\(\frac{19}{12}\)

Vậy x=\(\frac{-17}{4}\) hoặc    x= \(\frac{19}{12}\)

tk cho mk nha:)

Tk cho mk nha vì mk đang bị âm điểm.

cau co the ket ban voi mk bang nich nay khong,chigote

\(\frac{4}{3}B=-1+\frac{3}{4}-\left(\frac{3}{4}\right)^2+...+\left(\frac{3}{4}\right)^{99}\)

\(B=-\frac{3}{4}+\left(\frac{3}{4}\right)^2-\left(\frac{3}{4}\right)^3+...+\left(\frac{3}{4}\right)^{100}\)

\(\Rightarrow\)\(\frac{7}{3}B=-1+\left(\frac{3}{4}\right)^{100}\Rightarrow B=\frac{\left(\frac{3}{4}\right)^{100}-1}{\frac{7}{3}}=\frac{3\left[\left(\frac{3}{4}\right)^{100}-1\right]}{7}\)

Như vầy đủ gọn chưa bạn?

\(\frac{7}{6}+\frac{5}{6}:5-\frac{3}{8}.\left(-3\right)^2\)

\(=\frac{7}{6}+\frac{5}{6}.\frac{1}{5}-\frac{3}{8}.9\)

\(=\frac{7}{6}+\frac{1}{6}-\frac{27}{8}\)

\(=\frac{8}{6}-\frac{27}{8}\)

\(=\frac{32}{24}-\frac{81}{24}\)

\(=\frac{-49}{24}\)

Chúc bạn học tốt !!! 

5/8 + 0,2 : |-x/4 + 2/5| = 3/2

         0,2 : |-x/4 + 2/5| = 3/2 - 5/8 

         0,2 : |-x/4 + 2/5| = 7/8

                 |-x/4 + 2/5| = 7/8 . 0,2

                 |-x/4 + 2/5| = 7/40

\(\Rightarrow\orbr{\begin{cases}-\frac{x}{4}+\frac{2}{5}=\frac{7}{40}\\-\frac{x}{4}+\frac{2}{5}=-\frac{7}{40}\end{cases}\Rightarrow\orbr{\begin{cases}-\frac{x}{4}=-\frac{9}{40}\\-\frac{x}{4}=-\frac{23}{40}\end{cases}\Rightarrow}\orbr{\begin{cases}x=\frac{9}{10}\\x=\frac{23}{10}\end{cases}}}\)

 Báo cáo sai phạm

5/8 + 0,2 : |-x/4 + 2/5| = 3/2

         0,2 : |-x/4 + 2/5| = 3/2 - 5/8 

         0,2 : |-x/4 + 2/5| = 7/8

                 |-x/4 + 2/5| = 7/8 . 0,2

                 |-x/4 + 2/5| = 7/40

⇒[

⇒[

⇒[

\(\frac{5}{8}+0,2:\left|\frac{-x}{4}+\frac{2}{5}\right|=\frac{3}{2}\)

\(\Leftrightarrow\frac{33}{40}:\left|\frac{-x}{4}+\frac{2}{5}\right|=\frac{3}{2}\)

\(\Leftrightarrow\left|\frac{-x}{4}+\frac{2}{5}\right|=\frac{33}{40}:\frac{3}{2}\)

\(\Leftrightarrow\left|\frac{-x}{4}+\frac{2}{5}\right|=\frac{11}{20}\)

\(\Leftrightarrow\hept{\begin{cases}\Leftrightarrow\frac{-x}{4}+\frac{2}{5}=-\frac{11}{20}\\\Leftrightarrow\frac{-x}{4}+\frac{2}{5}=\frac{11}{20}\end{cases}}\Leftrightarrow\hept{\begin{cases}-\frac{x}{4}=\frac{-19}{20}\\\frac{-x}{4}=\frac{3}{20}\end{cases}\Leftrightarrow}\hept{\begin{cases}-x=-3,8\\-x=0,6\end{cases}}\Leftrightarrow\hept{\begin{cases}x=3,8\\x=-0,6\end{cases}}\)

Vậy :  \(x=3,8\) hoặc \(x=-0,6\)

TH1 : x < -1/30

=> 3/4 - 0,2 x = 3x + 0,1

=> 0,85 = 3,2 x 

=> x = 64/17 > -1/30 ( loại )

TH2 : 15/4 > x > -1/30

=> 3/4  - 0,2 x = -3x + 1

=> -1/4 = -3,2x

=> x = 12,8 > 15/4 ( loại )

TH3 : x > 15/4 

=> 0,2x - 3/4 = -3x + 0,1 

=> - 3,2x = -0,85

=> x = 17/64 < 15/4 ( loại )

Vậy x thuộc rỗng

Sửa -1/30 thành 1/30 nha bạn , kết quả không đổi

\(|0.2x-\frac{3}{4}|\)=\(|-3x+0.1|\)\(\Rightarrow\)0.2x-3/4=-3x+0.1 hoặc 0.2x-3/4=3x-0.1

*0.2x-3/4=-3x+0.1\(\Rightarrow\)3/4+1=-3x-0.2x\(\Rightarrow\)7/4=-3.2x\(\Rightarrow\)x=-37/16

*0.2x-3/4=3x-0.1\(\Rightarrow\)3/4+1=3x-0.2x\(\Rightarrow\)7/4=2.8x\(\Rightarrow\)x=37/14

nhớ tk mk nha

\(=\left(-0,37+\frac{14}{8}\right).\left(-1.1\right)-\left(2,63-\frac{9}{24}\right).\left(-1,1\right)\)

\(=-1,1.\left(-0,37+\frac{14}{8}-2,63+\frac{9}{24}\right)\)

\(=-1,1.\left[\left(-0,37-2,63\right)+\left(\frac{14}{8}+\frac{9}{24}\right)\right]\)

\(=-1,1.\left[\left(-3\right)+\left(\frac{14}{8}+\frac{3}{8}\right)\right]\)

\(=-1,1.\left(-3+\frac{17}{8}\right)\)

\(=-1,1.\left(-\frac{7}{8}\right)\)

\(=\frac{77}{80}\)

=77\80

B= 0,5 .4/3 .(-10) .0,75 .7/-35

B= 1/2 .4/3 .(-10) .3/4 .(-1)/5

B= [1/2 .(-1)/5 .(-10) ] .(4/3 .3/4)

B= 1 .1

B= 1

=1 nha

K MK NHA. CHÚC BẠN HỌC GIỎI

bn làm rõ 1 chút đi

\(\left|0,75-\frac{5}{4}x\right|=\left|-\frac{2}{3}x+\frac{5}{6}\right|\)

\(\Rightarrow\left|0,75-\frac{5}{4}x\right|-\left|-\frac{2}{3}x+\frac{5}{6}\right|=0\)

Mà GTTĐ luôn lớn hơn hoặc bằng 0

=> +) \(0,75-\frac{5}{4}x=0\)

\(\frac{5}{4}x=0,75\)

\(x=\frac{3}{5}\)

+) \(-\frac{2}{3}x+\frac{5}{6}=0\)

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

\(x=\frac{5}{4}\)

Vậy,.........

\(|\)0,75 - 5/4x\(|\)= \(|\)-2/3x +5/6 \(|\)

\(\Leftrightarrow\)0,75-5/4x = -2/3x+5/6 hoặc 0,75-5/4x=-(-2/3x+5/6)

TH1: 0,75-5/4x = -2/3x+5/6

\(\Leftrightarrow\)-5/4x+2/3x= 5/6-0,75

\(\Leftrightarrow\)-7/12x= 1/12

\(\Leftrightarrow\)x = 1/12 \(\div\)(-7/12)

\(\Leftrightarrow\)x = -1/7

TH2: 0,75-5/4x=-(-2/3x+5/6)

\(\Leftrightarrow\)0,75 - 5/4x= 2/3x-5/6

\(\Leftrightarrow\)-5/4x-2/3x = -5/6-0.75

\(\Leftrightarrow\)-23/12x= -19/12

\(\Leftrightarrow\)x=-(19/12)\(\div\)(-23/12)

\(\Leftrightarrow\)x=19/23

Vậy, x =-1/7 hoặc x= 19/23

từ  đề bài ta có thể suy ra 

0,75-5/4 x= -2/3x + 5/6 

-5/4x+2/3x = -0,75 + 5/6 

-7/12x           =        19/12

x=-19/7