Giúp mình với ạ h) ????+1/99 + ????+2/98 + ????+3/97 = -3 i) ????+11/12 + ????+10/13= ????+7/6 + ????+6/7 k) ????-5/19 + ????-6/18 + ????-29/5

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1. Giải thích các bước giải:

    Ta có:

   \(\begin{array}{l}
   h,\\
   \dfrac{{x + 1}}{{99}} + \dfrac{{x + 2}}{{98}} + \dfrac{{x + 3}}{{97}} =  – 3\\
    \Leftrightarrow \left( {\dfrac{{x + 1}}{{99}} + 1} \right) + \left( {\dfrac{{x + 2}}{{98}} + 1} \right) + \left( {\dfrac{{x + 3}}{{97}} + 1} \right) = 0\\
    \Leftrightarrow \dfrac{{\left( {x + 1} \right) + 99}}{{99}} + \dfrac{{\left( {x + 2} \right) + 98}}{{98}} + \dfrac{{\left( {x + 3} \right) + 97}}{{97}} = 0\\
    \Leftrightarrow \dfrac{{x + 100}}{{99}} + \dfrac{{x + 100}}{{98}} + \dfrac{{x + 100}}{{97}} = 0\\
    \Leftrightarrow \left( {x + 100} \right).\left( {\dfrac{1}{{99}} + \dfrac{1}{{98}} + \dfrac{1}{{97}}} \right) = 0\\
    \Leftrightarrow x + 100 = 0\\
    \Leftrightarrow x =  – 100\\
   k,\\
   \dfrac{{x – 5}}{{19}} + \dfrac{{x – 6}}{{18}} + \dfrac{{x – 29}}{5} + \dfrac{{x – 36}}{{18}} = 0\\
    \Leftrightarrow \left( {\dfrac{{x – 5}}{{19}} – 1} \right) + \left( {\dfrac{{x – 6}}{{18}} – 1} \right) + \left( {\dfrac{{x – 29}}{5} + 1} \right) + \left( {\dfrac{{x – 36}}{{18}} + 1} \right) = 0\\
    \Leftrightarrow \dfrac{{\left( {x – 5} \right) – 19}}{{19}} + \dfrac{{\left( {x – 6} \right) – 18}}{{18}} + \dfrac{{\left( {x – 29} \right) + 5}}{5} + \dfrac{{\left( {x – 36} \right) + 18}}{{18}} = 0\\
    \Leftrightarrow \dfrac{{x – 24}}{{19}} + \dfrac{{x – 24}}{{18}} + \dfrac{{x – 24}}{5} + \dfrac{{x – 24}}{{18}} = 0\\
    \Leftrightarrow \left( {x – 24} \right)\left( {\dfrac{1}{{19}} + \dfrac{1}{{18}} + \dfrac{1}{5} + \dfrac{1}{{18}}} \right) = 0\\
    \Leftrightarrow x – 24 = 0\\
    \Leftrightarrow x = 24
   \end{array}\)

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