Question

giúp mik vs ạ. mik c.ơn

Answer 1

Bài 5:

a) \(0,24\cdot-\dfrac{15}{4}=\dfrac{6}{25}\cdot-\dfrac{15}{4}=\dfrac{6\cdot-15}{25\cdot4}=-\dfrac{90}{100}=-\dfrac{9}{10}\)

b) \(4,5\cdot\dfrac{-4}{9}=\dfrac{9}{2}\cdot\dfrac{-4}{9}=\dfrac{9\cdot-4}{2\cdot9}=-\dfrac{4}{2}=-2\)

c) \(3,5\cdot-1\dfrac{2}{5}=\dfrac{7}{2}\cdot\dfrac{-7}{5}=\dfrac{7\cdot-7}{2\cdot5}=-\dfrac{49}{10}\)

Answer 2

Bài 6: 

a) \(1\dfrac{1}{17}\cdot\left(-2\dfrac{1}{8}\right)=\dfrac{18}{17}\cdot\dfrac{-17}{8}=\dfrac{18\cdot-17}{17\cdot8}=\dfrac{-18}{8}=-\dfrac{9}{4}\)

b) \(\left(-2\dfrac{1}{3}\right)\cdot1\dfrac{1}{14}=-\dfrac{7}{3}\cdot\dfrac{15}{14}=\dfrac{-7\cdot15}{3\cdot14}=-\dfrac{5}{2}\)

c) \(1,25\cdot\left(-3\dfrac{3}{8}\right)=\dfrac{5}{4}\cdot-\dfrac{27}{8}=\dfrac{5\cdot-27}{4\cdot8}=-\dfrac{135}{32}\)

Answer 3

`@` `\text {Ans}`

`\downarrow`

`5,`

`a)`

\(0,24\cdot\dfrac{-15}{4}\)

`= (0,24*(-15))/4`

`= (-3,6)/4 = -9/10`

`b)`

\(4,5\cdot\left(-\dfrac{4}{9}\right)\)

`= (4,5*(-4))/9`

`= -18/9 = -2`

`c)`

\(3,5\cdot\left(-1\dfrac{2}{5}\right)\)

`= 3,5*(-7/5)`

`= (3,5*(-7))/5`

`=(-24,5)/5 = -49/10`

`6,`

`a)`

\(1\dfrac{1}{17}\cdot\left(-2\dfrac{1}{8}\right)\)

`= 18/17 * (-17/8)`

`= -18/8 = -9/4`

`b)`

\(\left(-2\dfrac{1}{3}\right)\cdot1\dfrac{1}{14}\)

`= -7/3*15/14`

`= -1*5/2`

`= -5/2`

`c)`

\(1,25\cdot\left(-3\dfrac{3}{8}\right)\)

`= 1,25*(-27/8)`

`= (1,25*(-27))/8`

`= (-33,75)/8 = -135/32`