\(\frac{2}{3}\) .\(\frac{3}{4}\)\(\le\)\(\frac{x}{18}\) \(\le\)\(\frac{7}{3}\).\(\frac{1}{3}\)

\(\frac{1}{2}\le\frac{x}{18}\le\frac{7}{9}\)

\(\frac{9}{18}\le\frac{x}{18}\le\frac{14}{18}\)

\(\Rightarrow x\in\){9:10;11;12;13;14}

\(\frac{2}{3}.\left(\frac{1}{2}+\frac{3}{4}-\frac{1}{3}\right)\le\frac{x}{18}\le\frac{7}{3}.\left(\frac{1}{2}-\frac{1}{6}\right)\)

\(\frac{2}{3}.\left(\frac{5}{4}-\frac{1}{3}\right)\le\frac{x}{18}\le\frac{7}{3}.\frac{1}{3}\)

\(\frac{2}{3}.\frac{11}{12}\le\frac{x}{18}\le\frac{7}{9}\)

\(\frac{11}{18}\le\frac{x}{18}\le\frac{7}{9}\)

\(\frac{11}{18}\le\frac{x}{18}\le\frac{14}{18}\)

Vậy \(x\in\left\{11;12;13\right\}\)

\(\frac{2}{3}\cdot\left(\frac{1}{2}+\frac{3}{4}-\frac{1}{3}\right)\le\frac{x}{18}\le\frac{7}{3}\cdot\left(\frac{1}{2}-\frac{1}{6}\right)\)

\(\frac{2}{3}\cdot\left(\frac{2}{4}+\frac{3}{4}-\frac{1}{3}\right)\le\frac{x}{18}\le\frac{7}{3}\cdot\left(\frac{3}{6}-\frac{1}{6}\right)\)

\(\frac{2}{3}\cdot\left(\frac{5}{4}-\frac{1}{3}\right)\le\frac{x}{18}\le\frac{7}{3}\cdot\frac{1}{3}\)

\(\frac{2}{3}\cdot\left(\frac{15}{12}-\frac{4}{12}\right)\le\frac{x}{18}\le\frac{7}{9}\)

\(\frac{2}{3}\cdot\frac{11}{12}\le\frac{x}{18}\le\frac{7}{9}\)

\(\frac{11}{18}\le\frac{x}{18}\le\frac{14}{18}\)

Để \(x\)phải nhỏ hơn hoặc bằng thì x lần lượt bằng \(\left\{11;12;13;14\right\}\)

Sao đề khó đọc thế. Bạn viết rõ lại đi

thiếu dấu ngoặc rồi thánh!

\(4\frac{1}{3}.\left(\frac{1}{6}-\frac{1}{2}\right)\le x\le\frac{2}{3}.\left(\frac{1}{3}-\frac{1}{2}-\frac{3}{4}\right)\)

       \(\frac{13}{3}.\frac{-1}{3}\)   \(\le x\le\frac{2}{3}.\frac{-11}{12}\)

         \(\frac{-13}{9}\)        \(\le x\le\) \(\frac{-11}{18}\)

         \(\frac{-26}{18}\)     \(\le\frac{18x}{18}\le\frac{-11}{18}\)

Suy ra \(-26\le18x\le-11\)

\(\rightarrow x=-1\)

Vậy x = -1

Câu 1,

x+y=-1/3 ; y+z=5/4 ; x+z= 4/3

=> 2(x+y+z)=9/4

=> x+y+z=9/8

Ta lại có: x+y=-1/3

=> z=9/8 -(-1/3)=35/24

Ta lại có: z+y=5/4

=> y=-5/24

=> x=.....

Câu 2:

\(-4\le x\le-\frac{11}{18}\)

-4/1/3.1/3< x <  -2/3.-11/12

-1/4/9< x < 11/18

-26/18< x < 11/18

Vậy x={-26/18;-25/18;.............;11/18}