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3 tháng 11 2021

\(\frac{2^{13}.9^4}{6^6.8^3}\)

\(=\frac{2^{13}.\left(3^2\right)^4}{\left(2.3\right)^6.\left(2^3\right)^3}\)

\(=\frac{2^{13}.3^8}{2^6.3^6.2^9}\)

\(=\frac{2^{13}.3^8}{2^{15}.3^6}\)

\(=\frac{1.3^2}{2^2.1}\)

\(=\frac{3^2}{2^2}=\frac{9}{4}\)

\(a,\dfrac{2}{3}-\dfrac{5}{6}+\dfrac{3}{4}\)

\(=(\dfrac{2}{3}+\dfrac{3}{4})-\dfrac{5}{6}\)

\(=\dfrac{7}{12}\)

\(b,\dfrac{6}{7}.\dfrac{8}{13}+\dfrac{6}{13}.\dfrac{9}{7}-\dfrac{-4}{13}.\dfrac{6}{7}\)

\(=\dfrac{6}{7}.(\dfrac{8}{13}-\dfrac{4}{13})+(\dfrac{6}{13}.\dfrac{9}{7})\)

\(=(\dfrac{6}{7}.\dfrac{4}{13})+\dfrac{54}{91}\)

\(=\dfrac{24}{91}+\dfrac{54}{91}\)

\(=\dfrac{78}{91}=\dfrac{6}{7}\)

\(c,19.(-26)\)

\(=-494\)

28 tháng 3 2021

a) `2/3 - 5/6 +3/4`

`=4/6-5/6+3/4`

`=-1/6+3/4`

`=-4/24+18/24`

`=14/24=7/12`

b) `6/7 .8/13 +6/13 .9/7 -4/13 .6/7`

`=6/7 .(8/13-4/13) + 6/13 .9/7`

`=6/7 . 4/13 + 6/13 . 9/7`

`= 6/13 .4/7 +6/13 .9/7`

`=6/13 . (4/7+9/7)`

`=6/13 . 13/7`

`=6/7`

c) `19.(-26)`

`=(1-20).(20+6)`

`=20+6-400-120`

`=-494`

20 tháng 4 2022

Đề phải là `6 / 7 . 8 / 13 + 6 / 13 . 9 / 7 - 4 / 13 . 6 / 7` chứ nhỉ ?

20 tháng 4 2022

mk nhầm sửa lại rùi nha

  1.  6/7.8/13+6/13.9/7-3/13.6/7
  2. (-3,2).15/64+(0,8-2 4/15):3 2/3
  3. 1,4.15/49-(4/5+2/3):2 1/5

​/ là phân số

1 tháng 5 2016

1.=6/7.8/13+6/7.9/13-3/13.6/7=6/7.(8/13+9/13-3/13)=6/7.14/13=12/13

13 tháng 11 2021

\(\dfrac{2^{13}.9^4}{6^6.8^3}=\dfrac{2^{13}.3^8}{3^6.2^6.2^9}=\dfrac{2^{13}.3^8}{3^6.2^{15}}=\dfrac{3^2}{2^2}=\dfrac{9}{4}\)

26 tháng 4 2022

hehr

`@` `\text {Ans}`

`\downarrow`

\(\dfrac{2^8-2^3}{2^5-1}=\dfrac{2^3\left(2^5-1\right)}{2^5-1}=\dfrac{2^3}{1}=2^3=8\)

_____

\(\dfrac{4^8\cdot9^4}{6^6\cdot8^3}\)

`=`\(\dfrac{\left(2^2\right)^8\cdot\left(3^2\right)^4}{2^6\cdot3^6\cdot\left(2^3\right)^3}\)

`=`\(\dfrac{2^{16}\cdot3^8}{2^6\cdot3^6\cdot2^9}\)

`=`\(\dfrac{2^{16}\cdot3^8}{2^{15}\cdot3^6}\)

`=`\(\dfrac{3^2}{2}\) `=`\(\dfrac{9}{2}\)

______

\(\dfrac{27^4\cdot2^3-3^{10}\cdot4^3}{6^4\cdot9^3}\)

`=`\(\dfrac{\left(3^3\right)^4\cdot2^3-3^{10}\cdot\left(2^2\right)^3}{2^4\cdot3^4\cdot\left(3^2\right)^3}\)

`=`\(\dfrac{3^{12}\cdot2^3-3^{10}\cdot2^6}{2^4\cdot3^4\cdot3^6}\)

`=`\(\dfrac{3^{10}\cdot\left(3^2\cdot2^3-2^6\right)}{3^{10}\cdot2^4}\)

`=`\(\dfrac{72-2^6}{2^4}=\dfrac{8}{16}=\dfrac{1}{2}\)

11 tháng 7 2023

\(\dfrac{2^8-2^3}{2^5-1}=\dfrac{2^3\left(2^5-1\right)}{2^5-1}=2^3=8\)

\(\dfrac{4^8.9^4}{6^6.8^3}=\dfrac{2^{16}.3^8}{2^6.3^6.2^9}=2.3^2=18\)

\(\dfrac{27^4.2^3-3^{10}.4^3}{6^4.9^3}=\dfrac{3^{12}.2^3-3^{10}.2^6}{2^4.3^4.3^6}=\dfrac{2^3.3^{10}.\left(3^2-2^3\right)}{2^4.3^{10}}=\dfrac{9-8}{2}=\dfrac{1}{2}\)

20 tháng 4 2022

`6 / 7 . 8 / 13 + 6 / 13 . 9 / 7 - 4 / 13 . 6 / 7`

`= 6 / 7 . 8 / 13 + 6 / 7 . 9 / 13 - 4 / 13 . 6 / 7`

`= 6 / 7 ( 8 / 13 + 9 / 13 - 4 / 13 )`

`= 6 / 7 . 13 / 13`

`= 6 / 7`

20 tháng 4 2022

\(\dfrac{6}{7}.\dfrac{8}{13}+\dfrac{6}{13}.\dfrac{9}{7}-\dfrac{4}{13}.\dfrac{6}{7}\\ =\dfrac{6}{7}.\dfrac{8}{13}+\dfrac{6}{7}.\dfrac{9}{13}-\dfrac{4}{13}.\dfrac{6}{7}\\ =\dfrac{6}{7}\left(\dfrac{8}{13}+\dfrac{9}{13}-\dfrac{4}{13}\right)\\ =\dfrac{6}{7}.\dfrac{13}{13}\\ =\dfrac{6}{7}.1\\ =\dfrac{6}{7}\)

5 tháng 10 2017

\(\dfrac{2^{15}.9^4}{6^6.8^3}=\dfrac{2^{15}.\left(3^2\right)^4}{\left(3.2\right)^6.\left(2^3\right)^3}=\dfrac{2^{15}.3^8}{3^6.2^6.2^9}=\dfrac{2^{15}.3^6.3^2}{3^6.2^{15}}=3^2=9\)

6 tháng 9 2018

\(\frac{2^{15}\cdot9^4}{6^6\cdot8^3}=\frac{2^{15}\cdot3^4\cdot3^4}{2^6\cdot3^6\cdot\left(2^4\right)^3}=\frac{2^{12}\cdot2^3\cdot3^8}{2^6\cdot3^6\cdot2^{12}}\)

\(=\frac{2^3\cdot3^2\cdot3^6}{2^3\cdot2^3\cdot3^6}=\frac{3^3}{2^3}\)

\(=\frac{27}{8}\)

6 tháng 9 2018

\(\frac{2^{15}.9^4}{6^6.8^3}=\frac{\left(2^3\right)^5.\left(3^2\right)^4}{6^6.8^3}=\frac{8^5.3^8}{6^6.8^3}\)

\(=\frac{8^2.3^8}{6^6}=\frac{64.6561}{46656}=\frac{64.6561}{64.729}\)

\(=\frac{6561}{729}=9\)