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222-9+11+12:2*14+14 = ? ( )

Toán Lớp 6: a) 5/7 . -3/38 . 7/10 . 19/6 b) 3/7 . 9/11 + 3/7 . 5/11 – 3/7 . 25/11

Toán Lớp 6: a) 5/7 . -3/38 . 7/10 . 19/6
b) 3/7 . 9/11 + 3/7 . 5/11 – 3/7 . 25/11

Comments ( 2 )

  1. a) 5/7 .( -3)/38 . 7/10 . 19/6
    =(5.(-3).7.19)/(7.38.10.6)
    =(5.(-3).7.19)/(7.19.2.2.5.(-2).(-3))
    =((-3))/(2.2.(-2).(-3))
    =-1/8
    b) 3/7 . 9/11 + 3/7 . 5/11 – 3/7 . 25/11
    =3/7.(9/11+5/11-25/11)
    =3/7.(-11)/11
    =3/7.(-1)
    =-3/7
     

  2. #andy
    \[\begin{array}{l}
    a)\dfrac{5}{7}.\dfrac{{ – 3}}{{38}}.\dfrac{7}{{10}}.\dfrac{{19}}{6}\\
     = \dfrac{{5.\left( { – 3} \right).7.19}}{{7.38.10.6}}\\
     = \dfrac{{ – 1995}}{{15960}}\\
     =  – \dfrac{1}{8}\\
    b)\dfrac{3}{7}.\dfrac{9}{{11}} + \dfrac{3}{7}.\dfrac{5}{{11}} – \dfrac{3}{7}.\dfrac{{25}}{{11}}\\
     = \dfrac{3}{7}.\left( {\dfrac{9}{{11}} + \dfrac{5}{{11}} – \dfrac{{25}}{{11}}} \right)\\
     = \dfrac{3}{7}.\dfrac{{ – 11}}{{11}}\\
     = \dfrac{3}{7}.\left( { – 1} \right)\\
     =  – \dfrac{3}{7}
    \end{array}\]

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222-9+11+12:2*14+14 = ? ( )