Tính bằng hợp lí 4 11/23 + hỗn số 3 phân số 4/5 – 2 11/23 11 4/5 – (17 3/4 +11 4/5 ) +2 3/4 -27/26 – -5/21 +1/26 +16/21 + 50 phần trăm -2 2/3 + (0.

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1. Đáp án:

    $a) \dfrac{29}{5}\\
   b) -15\\
   c) \dfrac{1}{2}\\
   d) \dfrac{-161}{60}$

   Giải thích các bước giải:

    $a) 4\dfrac{11}{23}+3\dfrac{4}{5}-2\dfrac{11}{23}\\
   =\dfrac{103}{23}+\dfrac{19}{5}-\dfrac{57}{23}\\
   =\left ( \dfrac{103}{23}-\dfrac{57}{23} \right )+\dfrac{19}{5}\\
   =\dfrac{46}{23}+\dfrac{19}{5}\\
   =\dfrac{2.23}{23}+\dfrac{19}{5}\\
   =2+\dfrac{19}{5}\\
   =\dfrac{10}{5}+\dfrac{19}{5}\\
   =\dfrac{29}{5}\\
   b) 11\dfrac{4}{5}-\left ( 17\dfrac{3}{4}+11\dfrac{4}{5} \right )+2\dfrac{3}{4}\\
   =11\dfrac{4}{5}-17\dfrac{3}{4}-11\dfrac{4}{5} +2\dfrac{3}{4}\\
   =-17\dfrac{3}{4}+2\dfrac{3}{4}\\
   =-\dfrac{71}{4}+\dfrac{11}{4}\\
   =\dfrac{-60}{4}\\
   =-15\\
   c) \dfrac{-27}{26}–\dfrac{5}{21}+\dfrac{1}{26}+\dfrac{16}{21}+\dfrac{50}{100}\\
   =\left ( \dfrac{-27}{26}+\dfrac{1}{26} \right )+\left ( \dfrac{5}{21}+\dfrac{16}{21} \right )+\dfrac{50}{100}\\
   =\dfrac{-26}{26}+\dfrac{21}{21}+\dfrac{1}{2}\\
   =-1+1+\dfrac{1}{2}=\dfrac{1}{2}\\
   d) -2\dfrac{2}{3}+0,2-1,75+\dfrac{5}{6}+0,7\\
   =\dfrac{-8}{3}+\dfrac{2}{10}-\dfrac{7}{4}+\dfrac{5}{6}+\dfrac{7}{10}\\
   =\dfrac{-8}{3}-\dfrac{7}{4}+\dfrac{5}{6}+\left (\dfrac{2}{10}+\dfrac{7}{10}  \right )\\
   =\dfrac{-8}{3}-\dfrac{7}{4}+\dfrac{5}{6}+\dfrac{9}{10}\\
   =\dfrac{(-8).20}{60}-\dfrac{7.15}{60}+\dfrac{5.10}{60}+\dfrac{9.6}{60}\\
   =\dfrac{-160-105+50+54}{60}\\
   =\dfrac{-161}{60}$

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