Question

[cánh cụt]

3. \(\dfrac{5}{12}\) x (\(-\dfrac{3}{4}\))  + \(\dfrac{7}{12}\) x (\(-\dfrac{3}{4}\))

4. \(\dfrac{1}{7}\) x \(\dfrac{-3}{8}\) + \(\dfrac{1}{7}\) x \(\dfrac{-13}{8}\)

5. \(\dfrac{3}{5}\) x \(\dfrac{13}{46}\) - \(\dfrac{1}{10}\) x \(\dfrac{16}{23}\)

6. \(\dfrac{2}{3}\) -4 x (\(\dfrac{1}{2}\) + \(\dfrac{3}{4}\) )

Answer 1

[Chuu]

`5/12 xx (-3/4) + 7/12 xx (-3/4)`

`=(-3/4) xx (5/12 + 7/12)`

`=(-3)/4 xx ((5+7)/12)`

`=(-3)/4 xx 12/12`

`=(-3)/4 xx 1`

`=-3/4`

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`1/7 xx (-3)/8 + 1/7 xx (-13)/8`

`=1/7 xx (-3/8 + (-13)/8)`

`=1/7 xx `\(\left(\dfrac{-3+\left(-13\right)}{8}\right)\)

`=1/7xx (-16)/8`

`=1/7 xx (-2)`

`=-2/7`

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`3/5 xx 13/46 - 1/10 xx 16/23`

`= 3 xx 1/2 xx 1/5 xx 13/23 - 1/10 xx 16/23`

`= 3 xx 1/10 xx 13/23 - 1/10 xx 16/23`

`=1/10 xx ( 3xx13/23-16/23 )`

`=1/10 xx (38/23 - 16/23)`

`=1/10 xx 23/23`

`=1/10 x 1`

`=1/10`

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`2/3 - 4 xx ( 1/2 + 3/4)`

`=2/3 - 4 xx ( 2/4 + 3/4)`

`=2/3 - 4 xx 5/4`

`=2/3 - 5`

`=2/3 - 15/3`

`=-13/3`