\(\frac{3}{2}x-\frac{11}{5}=\frac{7}{8}.\frac{64}{49}\)

\(\frac{3}{2}x-\frac{11}{5}=\frac{8}{7}\)

\(\frac{3}{2}x=\frac{8}{7}+\frac{11}{5}=\frac{117}{35}\)

\(x=\frac{117}{35}:\frac{3}{2}=\frac{78}{35}\)

\(\frac{3}{2}x-\frac{11}{5}=\frac{7}{8}.\frac{64}{49}\) 

\(\frac{3}{2}x-\frac{11}{5}=\frac{8}{7}\)

\(\frac{3}{2}x=\frac{8}{7}+\frac{11}{5}\)

\(\frac{3}{2}x=\frac{117}{35}\)

\(x=\frac{117}{35}:\frac{3}{2}\)

\(x=\frac{78}{35}\)

A= 2^2019-2^2018-...-2^2-2^1-1 

??????

ÁP dụng tc dãy tỉ số bằng nhau ta có:

\(\frac{x}{3}=\frac{y}{5}=\frac{z}{7}=\frac{2x}{6}=\frac{3y}{15}=\frac{z}{7}=\frac{2x+3y-z}{6+15-7}=\frac{-14}{14}=-1\)

\(\Rightarrow x=-3;y=-5;z=-7\)

Đặt \(\frac{x}{3}=\frac{y}{5}=\frac{z}{7}=k\)

\(\Rightarrow x=3k;y=5k;z=7k\)

\(2x+3y-z=-14\)

\(\Leftrightarrow6k+15k-7k=-14\)

\(\Leftrightarrow14k=-14\)

\(\Leftrightarrow k=-1\)

\(\Rightarrow x=-3;y=-5;z=-7\)

\(\frac{-2}{3}.x+\frac{1}{5}=\frac{3}{10}\)

  \(\frac{-2}{3}.x=\frac{3}{10}-\frac{1}{5}=\frac{1}{10}\)

           \(x=\frac{1}{10}:\frac{-2}{3}=-\frac{3}{20}\)

Ta có : \(\frac{1}{6}x+\frac{1}{10}x-\frac{4}{15}x+1=0\)

<=> \(\frac{1}{6}x+\frac{1}{10}x-\frac{4}{15}x=-1\)

<=> \(\left(\frac{1}{6}+\frac{1}{10}-\frac{4}{15}\right)x=-1\)

<=> \(0.x=-1\)

=> x thuộc rỗng 

\(\frac{1}{6}x+\frac{1}{10}x-\frac{4}{15}x+1=0\)

\(\Leftrightarrow\left(\frac{1}{6}+\frac{1}{10}-\frac{4}{15}\right)x+1=0\)

\(\Leftrightarrow\left(\frac{5}{30}+\frac{3}{30}-\frac{8}{30}\right)x+1=0\)

\(\Leftrightarrow\frac{5+3-8}{30}x+1=0\)

\(\Leftrightarrow0x=-1\)(vô lí)

vậy không có giá trị nào của x thỏa mãn. 

x=4 cách lm tính vế trái sau đó đc -16/625 suy ra x= 4

Từ đề bài ta có:

4/3x - 1/3 = (2x-1) : 3/5 

=> 4/3x -1/3 = (2x-1) * 5/3

=> 4/3x -1/3= 10/3x - 5/3

Chuyển vế đổi dấu

Ta được:

=> -2x = -4/3

=> x= 2/3

Vậy x= 2/3

\(1\frac{1}{3}x=\left(2x-1\right):\left(1-\frac{2}{5}\right)\)

\(\frac{4}{3}x=\left(2x-1\right):\left(\frac{3}{5}\right)\)

\(\frac{4}{3}x.\frac{3}{5}=\left(2x-1\right)\)

\(\frac{4}{5}x=\left(2x-1\right)\)

\(x=\left(2x-1\right):\frac{4}{5}\)

\(x=\left(2x-1\right).\frac{5}{4}\)

\(x=2x.\frac{5}{4}-1.\frac{5}{4}\)

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

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

\(x=\left(\frac{5}{2}.x\right)-\frac{5}{4}\)

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

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

\(x=x\left(\frac{5}{4}-\frac{5}{4}\right)\)

\(x=x.0\)

\(=>x=0\)