\(\dfrac{1}{4}+\dfrac{8}{9}\le\dfrac{x}{36}\le1-\left(\dfrac{3}{8}-\dfrac{5}{6}\right)\\ \Rightarrow\dfrac{41}{36}\le\dfrac{x}{36}\le\dfrac{35}{24}\\ \Rightarrow\dfrac{82}{72}\le\dfrac{2x}{72}\le\dfrac{105}{72}\\ \Rightarrow41\le x< 51,5\)

\(\Leftrightarrow36\left(x+6\right)+36\left(x-6\right)=\dfrac{9}{2}\left(x^2-36\right)\)

\(\Leftrightarrow x^2\cdot\dfrac{9}{2}-162-72x=0\)

\(\Leftrightarrow9x^2-144x-324=0\)

\(\Leftrightarrow x^2-16x-36=0\)

=>(x-18)(x+2)=0

=>x=18 hoặc x=-2

ĐKXĐ:\(x\ne\pm6\)

\(\dfrac{36}{x-6}+\dfrac{36}{x+6}=4,5\\ \Leftrightarrow36\left(\dfrac{1}{x-6}+\dfrac{1}{x+6}\right)=4,5\\ \Leftrightarrow\dfrac{x+6}{\left(x-6\right)\left(x+6\right)}+\dfrac{x-6}{\left(x-6\right)\left(x+6\right)}=\dfrac{1}{8}\\ \Leftrightarrow\dfrac{x+6+x-6}{x^2-36}=\dfrac{1}{8}\\ \Leftrightarrow\dfrac{2x}{x^2-36}=\dfrac{1}{8}\\ \Leftrightarrow x^2-36=16x\\ \Leftrightarrow x^2-16x-36=0\\ \Leftrightarrow\left(x^2+2x\right)-\left(18x+36\right)=0\\ \Leftrightarrow x\left(x+2\right)-18\left(x+2\right)=0\\ \Leftrightarrow\left(x+2\right)\left(x-18\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}x=-2\left(tm\right)\\x=18\left(tm\right)\end{matrix}\right.\)

\(\dfrac{36}{x+6}+\dfrac{36}{x-6}=4,5\)

\(\Leftrightarrow36\left(x-6\right)+36\left(x+6\right)=4,5\left(x^2-36\right)\)

\(\Leftrightarrow36x-216+36x+216=4,5x^2-162\)

\(\Leftrightarrow-4,5x^2+72x+162=0\)

\(\Leftrightarrow\left(x-18\right)\left(-4,5x-9\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x=18\\x=-2\end{matrix}\right.\)

\(\dfrac{-7}{9}+\dfrac{-2}{9}=\dfrac{-9}{9}=-1\)

\(\dfrac{15}{4}-\dfrac{-3}{4}=\dfrac{18}{4}=\dfrac{9}{2}\)

\(\dfrac{1}{6}-\dfrac{1}{36}=\dfrac{6}{36}-\dfrac{1}{36}=\dfrac{5}{36}\)

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

\(2-\dfrac{4}{5}=\dfrac{10}{5}-\dfrac{4}{5}=\dfrac{6}{5}\)

a: \(=\dfrac{-6}{11}:\dfrac{3\cdot11}{4\cdot5}=\dfrac{-6}{11}\cdot\dfrac{20}{33}=\dfrac{-2}{11}\cdot\dfrac{20}{11}=\dfrac{-40}{121}\)

b: \(=\dfrac{7}{12}+\dfrac{5}{72}-\dfrac{11}{36}=\dfrac{42}{72}+\dfrac{5}{72}-\dfrac{22}{72}=\dfrac{25}{72}\)

c: \(=\dfrac{13}{10}:\dfrac{-5}{13}=\dfrac{-169}{50}\)

\(-\dfrac{2}{6}\)<\(\dfrac{x}{-36}\)

=>6x=(-2)(-36)

     6x=72

     x=12

Vậy x=12

\(\dfrac{12}{-36}\) <\(\dfrac{5}{y}\)

=>12y=(-36).5

     12y=-180

     y    =(-180):12

        y=-15

Vậy y=-15

\(\dfrac{36}{x^6}-\dfrac{24}{x^3}+4=\left(\dfrac{6}{x^3}\right)^2-2.\dfrac{6}{x^3}.2+2^2=\left(\dfrac{6}{x^3}-2\right)^2=4\left(\dfrac{3}{x^3}-1\right)\)

`(4^{-2}:(1/3)^2xx1/2)/((-1/6)^2)`
`=((1/16:1/9)xx1/2)/(1/36)`
`=36xx1/2xx(1/16xx9)`
`=18xx9/16`
`=81/8`

Đề sai rồi bạn

\(\dfrac{1}{2}\) là để giống m vuông í