a) 1/2-2/3x=7/12 b)3/4x+1/5=1/6 c)1/6x-3/8=1/4 giải hộ mình với

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1. a) $\dfrac{1}{2}-\dfrac{2}{3}x=\dfrac{7}{12}$

       $\dfrac{2}{3}x=\dfrac{1}{2}-\dfrac{7}{12}$

       $\dfrac{2}{3}x=\dfrac{-1}{12}$

       $x=\dfrac{-1}{12}:\dfrac{2}{3}$

       $x=\dfrac{-1}{8}$

   Vậy $x=\dfrac{-1}{8}$

   b) $\dfrac{3}{4}x+\dfrac{1}{5}=\dfrac{1}{6}$

        $\dfrac{3}{4}x=\dfrac{1}{6}-\dfrac{1}{5}$

        $\dfrac{3}{4}x=\dfrac{-1}{30}$

        $x=\dfrac{-1}{30}:\dfrac{3}{4}$

        $x=\dfrac{-2}{45}$

   Vậy $x=\dfrac{-2}{45}$

   c) $\dfrac{1}{6}x-\dfrac{3}{8}=\dfrac{1}{4}$

       $\dfrac{1}{6}x=\dfrac{1}{4}+\dfrac{3}{8}$

       $\dfrac{1}{6}x=\dfrac{5}{8}$

       $x=\dfrac{5}{8}:\dfrac{1}{6}$

       $x=\dfrac{15}{4}$

   Vậy $x=\dfrac{15}{4}$

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2. $\text { Đáp án: }$

   $ a) $

   ` 1/2 – 2/3 x = 7/12 `

   ` => 2/3 x = 1/2 – 7/12 `

   ` => 2/3 x = –1/12 `

   ` => x = –1/12 . 3/2 `

   ` => x = –1/8 `

   $ b) $

   ` 3/4 x + 1/5 = 1/6 `

   ` => 3/4 x = 1/6 – 1/5 `

   ` => 3/4 x = –1/30 `

   ` => x = –1/30 . 4/3 `

   ` => x = –2/45 `

   $ c) $

   ` 1/6 x – 3/8 = 1/4 `

   ` => 1/6 x = 1/4 + 3/8 `

   ` => 1/6 x = 5/8 `

   ` => x = 5/8 . 6 `

   ` => x = 15/4 `

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