-1 . \(\dfrac{5}{27}\) - \(\left(3x.\dfrac{7}{9^{ }}\right)^3\) = -\(\dfrac{24}{27}\)

\(\Rightarrow\) \(\dfrac{-5}{27}\) - \(\left(3x.\dfrac{7}{9^{ }}\right)^3\) = \(\dfrac{-24}{27}\)

\(\Rightarrow\) \(\left(3x.\dfrac{7}{9^{ }}\right)^3\) = \(\dfrac{-5}{27}\) - \(\dfrac{-24}{27}\) = \(\dfrac{19}{27}\)

\(\Rightarrow\) \(3^3\) . \(\dfrac{7^3}{3^6}\) = \(\dfrac{19}{3^3}\)

\(\Rightarrow\) \(\dfrac{x^3.7^3}{3^3}\) = \(\dfrac{19}{3^3}\)

\(\Rightarrow\) \(x^3\) . \(7^3\) = 19

=> [3x-7/9]^3= -8/27

=> 3x -7/9 = -2/3 => 3x = 1/9=> x= 1/27

đúng cái nhé

\(\frac{-32}{27}-\left(3x-\frac{7}{9}\right)^3=\frac{-24}{27}\)

\(-\left(3x-\frac{7}{9}\right)^3=\frac{-24}{27}+\frac{32}{27}\)

\(-\left(3x-\frac{7}{9}\right)^3=\frac{8}{27}\)

\(\left(3x-\frac{7}{9}\right)^3=\frac{-8}{27}\)

\(\left(3x-\frac{7}{9}\right)^3=\left(\frac{-2}{3}\right)^3\)

\(3x-\frac{7}{9}=\frac{-2}{3}\)

\(3x=\frac{-2}{3}+\frac{7}{9}\)

\(3x=\frac{1}{9}\)

\(x=\frac{1}{9}:3\)

\(x=\frac{1}{27}\)

\(V\text{ậy}\) \(x=\frac{1}{27}\)

Đây là cách làm đúng. Nhớ Lick cho mình nha !

Tô Phương Linh

\(\Leftrightarrow-\left(3x-\frac{7}{9}\right)^3=-\frac{24}{27}+\frac{32}{27}\)

\(\Leftrightarrow-\left(3x-\frac{7}{9}\right)^3=\frac{8}{27}\)

\(\Leftrightarrow\left(3x-\frac{7}{9}\right)^3=-\frac{8}{27}\)

\(\Leftrightarrow3x-\frac{7}{9}=-\frac{2}{3}\)

\(\Leftrightarrow3x=\frac{1}{9}\)

\(\Leftrightarrow x=\frac{1}{27}\)

siuu

Tìm x hả bạn ?

a ) \(\left(3x+\frac{1}{4}\right)^3=-27\)

\(\left(3x+\frac{1}{4}\right)^3=\left(-3\right)^3\)

\(\Rightarrow3x+\frac{1}{4}=-3\)

\(\Rightarrow3x=-3-\frac{1}{4}=-\frac{13}{4}\)

\(\Rightarrow x=-\frac{13}{4}:3=-\frac{13}{12}\)

Vậy x = \(-\frac{13}{12}\)

cho em hoi câu này xin các anh chị:

10mux x+4y = 2013

Cảm ơn Hoác Thiên Kình nhé .Thanh you 

a; \(\dfrac{93}{17}\): \(x\) + (- \(\dfrac{21}{17}\)) : \(x\) + \(\dfrac{22}{7}\): \(\dfrac{22}{3}\) = \(\dfrac{5}{14}\)

   \(\dfrac{94}{17}\) \(\times\) \(\dfrac{1}{x}\) - \(\dfrac{21}{17}\) \(\times\) \(\dfrac{1}{x}\) + \(\dfrac{3}{7}\) = \(\dfrac{5}{14}\)

    \(\dfrac{72}{17}\) \(\times\) \(\dfrac{1}{x}\) + \(\dfrac{3}{7}\) = \(\dfrac{5}{14}\)

     \(\dfrac{72}{17x}\)        = \(\dfrac{5}{14}\) - \(\dfrac{3}{7}\)

      \(\dfrac{72}{17x}\)      = - \(\dfrac{1}{14}\)

      17\(x\)       = 72.(-14)

       17\(x\)     = - 1008

         \(x\)       = - 1008 : 17

         \(x\)       = - \(\dfrac{1008}{17}\)

Vậy \(x\) \(=-\dfrac{1008}{17}\)

b; - \(\dfrac{32}{27}\) - (3\(x\) - \(\dfrac{7}{9}\))³ = - \(\dfrac{24}{27}\)

          - \(\dfrac{32}{27}\)  + \(\dfrac{24}{27}\) = (3\(x\) - \(\dfrac{7}{9}\))³ 

          (3\(x-\dfrac{7}{9}\))³ = - \(\dfrac{8}{27}\)

         (3\(x-\dfrac{7}{9}\))³ = (- \(\dfrac{2}{3}\))³

           3\(x-\dfrac{7}{9}\) = - \(\dfrac{2}{3}\)

           3\(x\)        = - \(\dfrac{2}{3}\) + \(\dfrac{7}{9}\)
           3\(x\)        = \(\dfrac{1}{9}\)

             \(x\)        = \(\dfrac{1}{9}\) : 3

             \(x\)       = \(\dfrac{1}{27}\)

Vậy \(x=\dfrac{1}{27}\)

Vũ Hồng Linh bạn check lại bài đầu dùm =_=" 

\(\left[-\frac{1}{3}\right]^3\cdot x=\frac{1}{81}\)

\(\Leftrightarrow x=\frac{1}{81}:\left[-\frac{1}{3}\right]^3\)

\(\Leftrightarrow x=\frac{1}{81}:\left[-\frac{1}{27}\right]\)

\(\Leftrightarrow x=\frac{1}{81}\cdot(-27)=-\frac{1}{3}\)

\(\left[x-\frac{1}{2}\right]^3=\frac{1}{27}\)

\(\Leftrightarrow\left[x-\frac{1}{2}\right]^3=\left[\frac{1}{3}\right]^3\)

=> Làm nốt 

Mấy bài kia cũng làm tương tự

27³⁴x27³³ ... 27³³x27³²

   bài có 2 cách: 

c1: vì cả 2 vế đều có 27³³ nên ta so sánh 2 số còn lại=> kết luận

c2: ta tính ra là so sánh 2 số : 27⁶⁷ và 27³⁵ => kết luận

dung roi do

27 mũ 132