Đáp án + Giải thích các bước giải:
` 9) (-11)/12 . 7/8 + 11/12 . (-15)/16 - 11/12`
`= 11/12 . (-7)/8 + 11/12 . (-15)/16 - 11/12`
`= 11/12 . ((-7)/8 + (-15)/16) - 11/12`
`= 11/12 . ((-14)/16 + (-15)/16) - 11/12`
`= 11/12 . (-29)/16 - 11/12`
`= (-319)/192 - 11/12`
`= (-319)/192 + (-176)/192`
`= (-495)/192 = (-165)/64`
`10) (19 5/8 : 7/12 - 13 1/4 : 7/12) . 4/5`
`= [(19 5/8 - 13 1/4) : 7/12] . 4/5`
`= {[(19 - 13) + (5/8 - 1/4)] : 7/12} . 4/5`
`= {[6 + (5/8 - 2/8)] : 7/12} . 4/5`
`= {[6 + 3/8] : 7/12} . 4/5`
`= {[48/8 + 3/8] : 7/12} . 4/5`
`= {51/8 . 12/7} . 4/5`
`= 102/7 . 4/5`
`= 408/35`
`11) (0,25 - 3/4) : (-2)/3 + ((-1)/2)^2`
`= (1/4 + (-3)/4) . (-3)/2 + 1/4`
`= (-1)/2 . (-3)/2 + 1/4`
`= 3/4 + 1/4`
`= 1`
`12) 1 13/15 . 0,75 - (11/20 + 25%) : 3/7`
`= 28/15 . 3/4 - (11/20 + 1/4) . 7/3`
`= 7/5 - (11/20 + 5/20) . 7/3`
`= 7/5 - 4/5 . 7/3`
`= 7/5 - 28/15`
`= 21/15 + (-28)/15`
`= (-7)/15`
`13) 2 2/3 . (-4)/5 . 0,375 . (-10) . (-15)/24`
`= 8/3 . (-4)/5 . 3/8 . (-10) . (-5)/8`
`= (8/3 . 3/8) . ((-4)/5 . (-5)/8) . (-10)`
`= 1 . 1/2 . (-10)`
`= 1/2 . (-10)`
`= -5`
`14) 2/3 - (75% + 2 1/6) + (-2)^3 . 0,5`
`= 2/3 - (3/4 + 13/6) + (-8) . 1/2`
`= 2/3 - (9/12 + 26/12) + (-4)`
`= 2/3 - 35/12 + (-4)`
`= 8/12 + (-35)/12 + (-48)/12`
`= (-27)/12 + (-48)/12`
`= (-75)/12 = (-25)/4`
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