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28 tháng 8 2017

= 1,5 + (-3/2) 

=     0

28 tháng 8 2017

=0 nha bn

9 tháng 12 2022

   0,75 + \(\dfrac{9}{5}\) ( 1,5 - \(\dfrac{2}{3}\) )2

= 0,75 + \(\dfrac{9}{5}\) ( \(\dfrac{3}{2}\) - \(\dfrac{2}{3}\))2

= 0,75 + \(\dfrac{9}{5}\) (\(\dfrac{5}{6}\))2

= 0,75 + \(\dfrac{5}{4}\)

= 0,75 + 1,25

= 2 

\(\dfrac{-22}{25}\) + ( \(\dfrac{22}{7}\) - 0,12)

\(\dfrac{-22}{25}\) + ( \(\dfrac{22}{7}\) - \(\dfrac{3}{25}\))

\(\dfrac{-22}{25}\) + \(\dfrac{22}{7}\) - \(\dfrac{3}{25}\)

= - ( \(\dfrac{22}{25}\) + \(\dfrac{3}{25}\)) + \(\dfrac{22}{7}\)

= -1 + \(\dfrac{22}{7}\)

\(\dfrac{-7}{7}\) + \(\dfrac{22}{7}\)

\(\dfrac{15}{7}\)

19 tháng 12 2022

a) \dfrac{3}{4}+\dfrac{9}{5}\left(\dfrac{3}{2}-\dfrac{2}{3}\right)^2=\dfrac{3}{4}+\dfrac{9}{5}\left(\dfrac{5}{6}\right)^2=\dfrac{3}{4}+\dfrac{9}{5} \cdot \dfrac{25}{36}=\dfrac{3}{4}+\dfrac{5}{4}=2

b) \dfrac{-22}{25}+\left(\dfrac{22}{7}-0,12\right)  =\dfrac{-22}{25}+\left(\dfrac{22}{7}-\dfrac{12}{100}\right)=\dfrac{-88}{100}+\dfrac{22}{7}+\dfrac{-12}{100}  =\left(\dfrac{-88}{100}+\dfrac{-12}{100}\right)+\dfrac{22}{7}=-1+\dfrac{22}{7}=\dfrac{15}{7}
 

 

12 tháng 12 2021

\(=\left(-\dfrac{2}{3}\right).\dfrac{3}{4}+\dfrac{5}{3}.\left(-\dfrac{9}{4}\right)+\dfrac{1}{4}=-\dfrac{1}{2}-\dfrac{15}{4}+\dfrac{1}{4}=-\dfrac{7}{2}-\dfrac{1}{2}=-4\)

16 tháng 12 2018

11/45

13 tháng 10 2021

=(7/8-1/4):(5/6-3/4)^2

=(7/8-2/8):(10/12-9/12)^2

=5/8-(1/12)^2

=5/8-1/144

=90/144-1/144

=89/144

HQ
Hà Quang Minh
Giáo viên
19 tháng 9 2023

\(a)\frac{2}{{15}} + \left( {\frac{{ - 5}}{{24}}} \right) = \frac{{16}}{{120}} + \left( {\frac{{ - 25}}{{120}}} \right) = \frac{{ - 9}}{{120}} = \frac{{ - 3}}{{40}}\)          

 b) \(\left( {\frac{{ - 5}}{9}} \right) - \left( { - \frac{7}{{27}}} \right) = \left( {\frac{{ - 15}}{{27}}} \right) + \frac{7}{{27}} = \frac{{ - 8}}{{27}}\)          

 c)\(\left( { - \frac{7}{{12}}} \right) + 0,75 = \left( { - \frac{7}{{12}}} \right) + \frac{75}{100} \\= \left( { - \frac{7}{{12}}} \right) + \frac{3}{4} \\= \left( { - \frac{7}{{12}}} \right) + \frac{9}{{12}} = \frac{2}{{12}} = \frac{1}{6}\)

d)\(\left( {\frac{{ - 5}}{9}} \right) - 1,25 =\left( {\frac{{ - 5}}{9}} \right) - \frac{125}{100} = \left( {\frac{{ - 5}}{9}} \right) - \frac{5}{4}\\ = \left( {\frac{{ - 20}}{{36}}} \right) - \frac{{45}}{{36}} = \frac{{ - 65}}{{36}}\)       

 e)\(0,34.\frac{{ - 5}}{{17}} =\frac{{34}}{{100}}.\frac{{ - 5}}{{17}} = \frac{{17}}{{50}}.\frac{{ - 5}}{{17}} = \frac{{ - 1}}{{10}}\)                       

g) \(\frac{4}{9}:\left( { - \frac{8}{{15}}} \right) = \frac{4}{9}.\left( { - \frac{{15}}{8}} \right) = \frac{{ - 5}}{6}\)

h)\(\left( {1\frac{2}{3}} \right):\left( {2\frac{1}{2}} \right) = \frac{5}{3}:\frac{5}{2} = \frac{5}{3}.\frac{2}{5} = \frac{2}{3}\)       

i) \(\frac{2}{5}.\left( { - 1,25} \right) = \frac{2}{5}.\frac{{ - 125}}{100} = \frac{2}{5}.\frac{{ - 5}}{4} = \frac{{ - 1}}{2}\)                     

k) \(\left( {\frac{{ - 3}}{5}} \right).\left( {\frac{{15}}{{ - 7}}} \right).3\frac{1}{9} = \left( {\frac{{ - 3}}{5}} \right).\left( {\frac{{15}}{{ - 7}}} \right).\frac{{28}}{9}\\ = \frac{{ - 3.3.5.7.4}}{{5.\left( { - 7} \right).3.3}} = 4\)

18 tháng 4 2017

Các câu sai: a, c, d, f

Các câu đúng: b, e


7 tháng 5 2017

Các câu đúng: b,e
Các câu sai: a, c, d; f.
a) \(\left(-5\right)^2.\left(-5\right)^3=\left(-5\right)^5\);
c) \(\left(0,2\right)^{10}:\left(0,2\right)^5=\left(0,2\right)^{10-5}=0,2^5\);
d) \(\left[\left(-\dfrac{1}{7}\right)^2\right]^4=\left(-\dfrac{1}{7}\right)^{2.4}=\left(-\dfrac{1}{7}\right)^8\)
f \(\dfrac{8^{10}}{4^8}=\dfrac{\left(2^3\right)^5}{\left(2^2\right)^8}=\dfrac{2^{15}}{2^{16}}=\dfrac{1}{2}\)

\(\Leftrightarrow\left(\dfrac{-3}{4}x+\dfrac{5}{2}\right)\cdot\dfrac{4}{7}=\dfrac{-5}{6}-\dfrac{1}{3}=\dfrac{-4}{3}\)

\(\Leftrightarrow-\dfrac{3}{4}x+\dfrac{5}{2}=\dfrac{-4}{3}:\dfrac{4}{7}=\dfrac{-7}{3}\)

=>-3/4x=-29/6

hay x=58/9

20 tháng 5 2022

`(-0,75.x+5/2). 4/7-(-1/3)=[-5]/6`

`(-3/4 .x+5/2). 4/7=-7/6`

`-3/4 .x+5/2=-49/24`

`-3/4 .x=-109/24`

`x=109/18`

HQ
Hà Quang Minh
Giáo viên
19 tháng 9 2023

a)\({\left( {\frac{2}{5} + \frac{1}{2}} \right)^2} = {\left( {\frac{4}{{10}} + \frac{5}{{10}}} \right)^2} = {\left( {\frac{9}{{10}}} \right)^2} = \frac{{81}}{{100}}\);               

 b)\({\left( {0,75 - 1\frac{1}{2}} \right)^3} = {\left( {\frac{3}{4} - \frac{3}{2}} \right)^3} = {\left( {\frac{3}{4} - \frac{6}{4}} \right)^3} = {\left( { - \frac{3}{4}} \right)^3} = \frac{{ - 27}}{{64}};\)

c)

\(\begin{array}{l}{\left( {\frac{3}{5}} \right)^{15}}:{\left( {0,36} \right)^5} = {\left( {\frac{3}{5}} \right)^{15}}:{\left( {\frac{9}{{25}}} \right)^5}\\ = {\left( {\frac{3}{5}} \right)^{15}}:{\left[ {{{\left( {\frac{3}{5}} \right)}^2}} \right]^5} = {\left( {\frac{3}{5}} \right)^{15}}:{\left( {\frac{3}{5}} \right)^{10}} = {\left( {\frac{3}{5}} \right)^5}\end{array}\)

d) \({\left( {1 - \frac{1}{3}} \right)^8}:{\left( {\frac{4}{9}} \right)^3} = {\left( {\frac{3}{3} - \frac{1}{3}} \right)^8}:{\left( ({\frac{2}{3}})^2 \right)^3}\\= {\left( {\frac{2}{3}} \right)^8}:{\left( {\frac{2}{3}} \right)^6} = {\left( {\frac{2}{3}} \right)^{8-6}}\\= {\left( {\frac{2}{3}} \right)^2} = \frac{4}{9}\)