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\(=\dfrac{35.85\cdot14}{0.5+2.3}\cdot\dfrac{6}{17}\cdot\dfrac{16.8}{259,2}-\left(4.625-\dfrac{13}{6}:\dfrac{26}{3}\right):\left(3.25:2.25\right)\)

\(=\dfrac{1673}{408}-\dfrac{315}{104}=\dfrac{1421}{1326}\)

6 tháng 7 2019

b) Ta có: \(|x-3,5|\ge0;\forall x\)

\(\Rightarrow|x-3,5|+2,3\ge2,3;\forall x\)

\(\Rightarrow\frac{4,6}{|x-3,5|+2,3}\le\frac{4,6}{2,3};\forall x\)

Hay \(I\le2;\forall x\)

Dấu "=" xảy ra \(\Leftrightarrow|x-3,5|=0\)

                        \(\Leftrightarrow x=3,5\)

Vậy MAX I =2 \(\Leftrightarrow x=3,5\)

6 tháng 7 2019

a) Ta có: \(\hept{\begin{cases}|x+2,1|\ge0;\forall x\\|y-4,6-2015|\ge0;\forall y\end{cases}}\)

\(\Rightarrow\hept{\begin{cases}-|x+2,1|\le0;\forall x\\-|y-2019,6|\le0;\forall x\end{cases}}\)

\(\Rightarrow-|x+2,1|-|y-2019,6|\le0;\forall x,y\)

Hay \(G\le0;\forall x,y\)

Dấu "=" xảy ra \(\Leftrightarrow\hept{\begin{cases}|x+2,1|=0\\|y-2019,6|=0\end{cases}}\)

                        \(\Leftrightarrow\hept{\begin{cases}x=-2,1\\y=2019,6\end{cases}}\)

Vậy MAX G=0 \(\Leftrightarrow\hept{\begin{cases}x=-2,1\\y=2019,6\end{cases}}\)

29 tháng 8 2015

\(x:\frac{13}{10}+\frac{42}{5}.\frac{6}{7}.\left(6-\frac{\left(2,3+0,8\right).7}{0,1+6,9}\right)=\frac{39}{7}:\frac{15}{14}=\frac{37}{7}.\frac{14}{15}=\frac{74}{15}\)

\(x.\frac{10}{13}+\frac{36}{7}\left(6-\frac{3,1.7}{7}\right)=\frac{74}{15}\)

\(x.\frac{10}{13}+\frac{36}{7}\left(6-3,1\right)=\frac{74}{15}\)

\(x.\frac{10}{13}+\frac{36}{7}.\frac{29}{10}=\frac{74}{15}\)

\(x.\frac{10}{13}+\frac{522}{35}=\frac{74}{15}\)

\(x.\frac{10}{13}=\frac{74}{15}-\frac{522}{35}=-9\frac{103}{105}\)

\(x=-9\frac{103}{105}:\frac{10}{13}=-12\frac{512}{525}\)

 

 

 

29 tháng 8 2015

Ngan Nguyen

nhấn "Shift" rồi "\"

8 tháng 8 2019

c) \(\frac{x-1}{2009}+\frac{x-2}{2008}=\frac{x-3}{2007}+\frac{x-4}{2006}\)

\(\Leftrightarrow\left(\frac{x-1}{2009}-1\right)+\left(\frac{x-2}{2008}-1\right)=\left(\frac{x-3}{2007}-1\right)+\left(\frac{x-4}{2006}-1\right)\)

\(\Leftrightarrow\frac{x-2010}{2009}+\frac{x-2010}{2008}-\frac{x-2010}{2007}-\frac{x-2010}{2006}=0\)

\(\Leftrightarrow\left(x-2010\right).\left(\frac{1}{2009}+\frac{1}{2008}-\frac{1}{2007}-\frac{1}{2006}\right)=0\)

\(\Leftrightarrow x-2010=0\)

\(\Leftrightarrow x=0+2010\)

\(\Rightarrow x=2010\)

Vậy \(x=2010.\)

Mình chỉ làm câu c) thôi nhé.

Chúc bạn học tốt!

HQ
Hà Quang Minh
Giáo viên
19 tháng 9 2023

a)

\(\begin{array}{l}A = \frac{5}{{11}}.\left( {\frac{{ - 3}}{{23}}} \right).\frac{{11}}{5}.\left( { - 4,6} \right)\\A = \frac{5}{{11}}.\left( {\frac{{ - 3}}{{23}}} \right).\frac{{11}}{5}.\frac{{ - 23}}{5}\\A = \frac{{5.\left( { - 3} \right).11.\left( { - 23} \right)}}{{11.23.5.5}}\\A = \frac{3}{5}\end{array}\)  

b)

\(\begin{array}{l}B = \left( {\frac{{ - 7}}{9}} \right).\frac{{13}}{{25}} - \frac{{13}}{{25}}.\frac{2}{9}\\B = \frac{{13}}{{25}}.\left( {\frac{{ - 7}}{9} - \frac{2}{9}} \right)\\B = \frac{{13}}{{25}}.(-1)\\B = \frac{{-13}}{{25}}.\end{array}\)

25 tháng 7 2017

\(=\frac{16}{5}.\frac{15}{16}-\left(\frac{3}{4}+\frac{2}{7}\right):\left(\frac{-29}{28}\right)\)

\(=3-\left(\frac{21}{28}+\frac{8}{28}\right):\left(\frac{-29}{28}\right)\)

\(=3-\left(\frac{29}{28}\right).\left(\frac{-28}{29}\right)\)

\(=3-\left(-1\right)\)

\(=4\)

b)   \(=\left(\frac{1}{4}+\frac{25}{2}-\frac{5}{16}\right):\left(12-\frac{7}{12}:\left(\frac{3}{8}-\frac{1}{12}\right)\right)\)

       \(=\left(\frac{4}{16}+\frac{200}{16}-\frac{5}{16}\right):\left(12-\frac{7}{12}:\left(\frac{3.3}{2.3.4}-\frac{2}{2.3.4}\right)\right)\)

     \(=\left(\frac{199}{16}\right):\left(12-\frac{7}{12}:\left(\frac{9}{24}-\frac{2}{24}\right)\right)\)

      \(=\frac{199}{16}:\left(12-\frac{7}{12}.\frac{24}{7}\right)\)

    \(=\frac{199}{16}:\left(12-2\right)\)

\(=\frac{199}{16}:10\)

\(=\frac{199}{160}\)

c)   \(\left(\frac{-3}{5}+\frac{5}{11}\right):\frac{-3}{7}+\left(\frac{-2}{5}+\frac{6}{5}\right):\frac{-3}{7}\)

\(\left(\frac{-33}{55}+\frac{25}{55}\right):\frac{-3}{7}+\left(\frac{4}{5}\right):\frac{-3}{7}\)

\(\left(\frac{-8}{55}\right).\frac{-7}{3}+\frac{4}{5}.\frac{-7}{3}\)

\(\frac{-7}{3}\left(\frac{-8}{55}+\frac{4}{5}\right)\)

\(\frac{-7}{3}.\frac{36}{55}=\frac{-84}{55}\)

     

25 tháng 7 2017

giờ mk phải đi ngủ r mai mk làm cho