Tính C = (3/10 – 4/15 – 7/20) + -5/19 / (1/14 + 1/7 – (-3)/35) . 4/3 20/07/2021 Bởi Serenity Tính C = (3/10 – 4/15 – 7/20) + -5/19 / (1/14 + 1/7 – (-3)/35) . 4/3
Đáp án: $C=\dfrac{-481}{1140}$ Giải thích các bước giải: $C=\left ( \dfrac{3}{10}-\dfrac{4}{15}-\dfrac{7}{20} \right )+\dfrac{-5}{19}\left ( \dfrac{1}{14}+\dfrac{1}{7}-\dfrac{-3}{35} \right ).\dfrac{4}{3}\\=\left ( \dfrac{18}{60}-\dfrac{16}{60}-\dfrac{21}{60} \right )+\dfrac{-5}{19}\left ( \dfrac{15}{210}+\dfrac{30}{210}-\dfrac{-18}{210} \right ).\dfrac{4}{3}\\=\dfrac{-19}{60}+\dfrac{-5}{19}.\dfrac{63}{210}.\dfrac{4}{3}\\=\dfrac{-19}{60}+\dfrac{-3}{38}.\dfrac{4}{3}\\=\dfrac{-19}{60}+\dfrac{-2}{19}\\=\dfrac{-361}{1140}+\dfrac{-120}{1140}\\=\dfrac{-481}{1140}$ Bình luận
Đáp án:
$C=\dfrac{-481}{1140}$
Giải thích các bước giải:
$C=\left ( \dfrac{3}{10}-\dfrac{4}{15}-\dfrac{7}{20} \right )+\dfrac{-5}{19}\left ( \dfrac{1}{14}+\dfrac{1}{7}-\dfrac{-3}{35} \right ).\dfrac{4}{3}\\
=\left ( \dfrac{18}{60}-\dfrac{16}{60}-\dfrac{21}{60} \right )+\dfrac{-5}{19}\left ( \dfrac{15}{210}+\dfrac{30}{210}-\dfrac{-18}{210} \right ).\dfrac{4}{3}\\
=\dfrac{-19}{60}+\dfrac{-5}{19}.\dfrac{63}{210}.\dfrac{4}{3}\\
=\dfrac{-19}{60}+\dfrac{-3}{38}.\dfrac{4}{3}\\
=\dfrac{-19}{60}+\dfrac{-2}{19}\\
=\dfrac{-361}{1140}+\dfrac{-120}{1140}\\
=\dfrac{-481}{1140}$
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