Question

[BÙI BẢO KHÁNH]

Bài 4:Tính

-5/8 : 15/4

-15/17 : 25/-34

-12:8/3

-15/14:20/-21

-48:(-24/5)

-30/7:(-5/-14)

15/28 : (-9/14)

-7/40:(-21/20)

-30/21:(15/-7)

48/-25:(24/-15)

-18/25:(-9/50)

5 1/3:(-8/9)

Các bạn ơi giúp mình vs ạ,mình đang cần gấp !!!!!!!!!

Answer 1

[HT.Phong (9A5)]

\(\dfrac{-5}{8}:\dfrac{15}{4}=\dfrac{-5}{8}\cdot\dfrac{4}{15}=\dfrac{-1\cdot1}{2\cdot3}=\dfrac{-1}{6}\)

\(\dfrac{-15}{17}:\dfrac{25}{-34}=\dfrac{-15}{17}\cdot\dfrac{-34}{25}=\dfrac{-3\cdot-2}{1\cdot5}=\dfrac{-6}{5}\)

\(-12:\dfrac{8}{3}=-12\cdot\dfrac{3}{8}=\dfrac{-12\cdot3}{8}=\dfrac{-3\cdot3}{2}=\dfrac{-9}{2}\)

\(\dfrac{-15}{14}:\dfrac{20}{-21}=\dfrac{-15}{14}\cdot\dfrac{-21}{20}=\dfrac{-3\cdot-3}{2\cdot4}=\dfrac{-9}{8}\)

\(-48:\dfrac{-24}{5}=-48\cdot\dfrac{5}{-24}=\dfrac{-48\cdot5}{-24}=2\cdot5=10\) 

\(\dfrac{-30}{7}:\dfrac{-5}{-14}=\dfrac{-30}{7}:\dfrac{5}{14}=\dfrac{-30}{7}\cdot\dfrac{14}{5}=\dfrac{-6\cdot2}{1\cdot1}=-18\)