a)M=$\frac{-1}{6}$-$\frac{2}{3}$.$\frac{-3}{4}$+$\frac{(-2)^{2}}{5}$ b)2$\frac{2}{9}$-1$\frac{1}{9}$- a)M=$\frac{-1}{6}$-$\frac{2}{3}$.$\frac{-3}{4}$+

Bởi

a)M=$\frac{-1}{6}$-$\frac{2}{3}$.$\frac{-3}{4}$+$\frac{(-2)^{2}}{5}$
b)2$\frac{2}{9}$-1$\frac{1}{9}$- a)M=$\frac{-1}{6}$-$\frac{2}{3}$.$\frac{-3}{4}$+$\frac{(-2)^{2}}{5}$
b)2$\frac{2}{9}$-1$\frac{1}{9}$-$\frac{46}{5}$.$\frac{5}{23}$+$\frac{4}{3}$
c)N=$\frac{2}{3.5}$+$\frac{2}{5.7}$+$\frac{2}{7.9}$+$\frac{2}{9.11}$+$\frac{2}{11.13}$+$\frac{2}{13.15}$

0 bình luận về “a)M=$\frac{-1}{6}$-$\frac{2}{3}$.$\frac{-3}{4}$+$\frac{(-2)^{2}}{5}$ b)2$\frac{2}{9}$-1$\frac{1}{9}$- a)M=$\frac{-1}{6}$-$\frac{2}{3}$.$\frac{-3}{4}$+”

  1. `a) M= (-1)/6  -2/3 . (-3)/4 + (-2)^2/5`
    ` = (-1)/6 + 1/2 + 4/5`
    ` = 1/3 + 4/5`
    ` = 17/15`

    Vậy `M=17/15`

    `b) 2 2/9 – 1 1/9 – 46/5 . 5/23 + 4/3`
    ` = 20/9 – 10/9 – 2  +4/3`
    ` = 10/9 – 2 + 4/3`
    ` = -8/9 + 4/3`
    ` = 4/9`

    `c) N = 2/3.5 + 2/5.7 + 2/7.9 + 2/9.11 + 2/11.13 + 2/13.15`
    ` = 1/3 – 1/5 + 1/5 – 1/7 + 1/7-1/9+1/9-1/11+1/11-1/13+1/13-1/15`
    ` = 1/3 – 1/15`
    ` = 4/15`

    Vậy `N=4/15`

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  2. Đáp án:

    $a/$ `M=  (-1)/6 – 2/3 . (-3)/4 + (-2)^2/5`

    `-> M = (-1)/6 + 1/2 + 4/5`

    `-> M = 1/3 + 4/5`

    `-> M = 17/15`

    `text{Vậy}` `M = 17/15`

    $b/$ `2 2/9 – 1 1/9 – 46/5 . 5/23 + 4/3`

    `= 20/9 – 10/9 – 2 + 4/3`

    `= 10/9 – 2 + 4/3`

    `= (-8)/9 + 4/3`

    `= 4/9`

    $c/$ `N = 2/(3 . 5) + 2/(5 . 7) + 2/(7 . 9) + 2/(9 . 11) + 2/(11 . 13) + 2/(13 . 15)`

    `-> N = 1/3 – 1/5 + 1/5 – 1/7 + 1/7 – 1/9 + 1/9 – 1/11 + 1/11 – 1/13 + 1/13 – 1/15`

    `-> N = 1/3 + (- 1/5 + 1/5 – 1/7 + 1/7 – 1/9 + 1/9 – 1/11 + 1/11 – 1/13 + 1/13) -1/15`

    `-> N = 1/3 – 1/15`

    `-> N =4/15`

    `text{Vậy}` `N = 4/15`

     

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