`a) ((-14).15)/(21.(-10))`

`=(-7.3.5.3)/(7.3.(-2).5)`

`=3/2`

`b) ((-7).12)/((-16).(-14))`

`=(-7.3.2.2)/(-2.2.2.(-7).2)`

`=(-3)/4`

`c) ((-11).(-5))/(15.22) `

`=(-11.(-5))/(3.5.11.2)`

`=1/6`

`d) ((-10).(-18))/((-6).25.7)`

`=(-5.2.-2.3.3)/(-2.3.5.5.7)`

`=6/35`

`e) (5.7-7.9)/(7.2+6.7)`

`=(7.(5-9))/(7.(2+6))`

`=-4/8`

`=-1/2`

`f) (11.9-22.3)/(33.2)`

`=(33.(3-2))/(33.2)`

`=1/2`

ta có: \(\frac{-5}{7}.\frac{2}{11}+\frac{-5}{7}.\frac{9}{11}\)

           \(=\frac{-5}{7}.\left(\frac{2}{11}+\frac{9}{11}\right)\)

             \(=\frac{-5}{7}\)

\(\Rightarrow\frac{-5}{7}< \frac{5}{7}\)

\(\Rightarrow\frac{-5}{7}.\frac{2}{11}+\frac{-5}{7}.\frac{9}{11}< \frac{5}{7}\)

Học tốt nhé bn !!!

\(\left(-\dfrac{1}{2}\right)^2\div\dfrac{1}{4}-2\times\left(-\dfrac{1}{2}\right)^2\\= \dfrac{1}{4}\div\dfrac{1}{4}-2\times\dfrac{1}{4}\\ =1-\dfrac{1}{2}\\ =\dfrac{1}{2}\)

\(\left(-2\right)^3\times-\dfrac{1}{24}+\left(\dfrac{4}{3}-1\dfrac{5}{6}\right)\div\dfrac{5}{12}\)

=  \(-6\times-\dfrac{1}{24}+\left(\dfrac{4}{3}-\dfrac{11}{6}\right)\div\dfrac{5}{12}\)

=  \(\dfrac{1}{4}+-\dfrac{1}{2}\div\dfrac{5}{12}\)

=  \(\dfrac{1}{4}+-\dfrac{6}{5}\)

=  \(\dfrac{1}{4}-\dfrac{6}{5}\)

=  \(-\dfrac{19}{20}\)

\(\left(6\dfrac{4}{9}+\dfrac{7}{11}\right)-\left(4\dfrac{4}{9}-2\dfrac{4}{11}\right)\\ =\dfrac{58}{9}+\dfrac{7}{11}-\dfrac{40}{9}+\dfrac{26}{11}\\ =\dfrac{58}{9}-\dfrac{40}{9}+\dfrac{7}{11}+\dfrac{26}{11}\\ =12+3\\ =15\)

\(a,\left(\dfrac{-1}{2}\right)^2:\dfrac{1}{4}-2\left(-\dfrac{1}{2}\right)^2\)

\(=\left(-\dfrac{1}{2}\right)^2\left(4-2\right)\)

\(=\dfrac{1}{4}.2=\dfrac{1}{2}\)

\(b,\left(-2\right)^3.\dfrac{-1}{24}+\left(\dfrac{4}{3}-1\dfrac{5}{6}\right):\dfrac{5}{12}\)

\(=\left(-8\right).\dfrac{-1}{24}+\left(-\dfrac{1}{2}\right).\dfrac{12}{5}\)

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

\(c,\left(6\dfrac{4}{9}+\dfrac{7}{11}\right)-\left(4\dfrac{4}{9}-2\dfrac{4}{11}\right)\)

\(=\dfrac{701}{99}-\dfrac{206}{99}=\dfrac{495}{99}=5\)

\(d,10\dfrac{1}{5}-5\dfrac{1}{2}.\dfrac{60}{11}+\dfrac{3}{15\%}\)

\(=\dfrac{51}{5}-30+20=\dfrac{1}{5}\)

\(e,\dfrac{5}{7}.\dfrac{5}{11}+\dfrac{5}{7}.\dfrac{2}{11}-\dfrac{5}{7}.\dfrac{14}{11}\)

\(=\dfrac{5}{7}\left(\dfrac{5}{11}+\dfrac{2}{11}-\dfrac{14}{11}\right)=\dfrac{5}{7}.\left(-\dfrac{7}{11}\right)\)

\(=-\dfrac{5}{11}\)

\(f,\dfrac{-5}{7}.\dfrac{2}{11}+\left(-\dfrac{5}{7}\right).\dfrac{9}{11}+1\dfrac{5}{7}\)

\(=\left(-\dfrac{5}{7}\right)\left(\dfrac{2}{11}+\dfrac{9}{11}\right)+\dfrac{12}{7}\)

\(=\left(-\dfrac{5}{7}\right)+\dfrac{12}{7}=1\)

\(10\dfrac{1}{5}-5\dfrac{1}{2}\times\dfrac{60}{11}+3\div15\%\\ =\dfrac{51}{5}-\dfrac{11}{2}\times\dfrac{60}{11}+3\div\dfrac{15}{100}\\ =\dfrac{51}{5}-30+20\\ =10,2-30+20\\ =0,2\)

\(\dfrac{5}{7}\times\dfrac{5}{11}+\dfrac{5}{7}\times\dfrac{2}{11}-\dfrac{5}{7}\times\dfrac{14}{11}\\ =\dfrac{5}{7}\times\left(\dfrac{5}{11}+\dfrac{2}{11}-\dfrac{14}{11}\right)\\ =\dfrac{5}{7}\times-\dfrac{7}{11}=-\dfrac{5}{11}\)

\(-\dfrac{5}{7}\times\dfrac{2}{11}+-\dfrac{5}{7}\times\dfrac{9}{11}+1\dfrac{5}{7}\\ =-\dfrac{5}{7}\times\dfrac{2}{11}+-\dfrac{5}{7}\times\dfrac{9}{11}+\dfrac{12}{7}\\ =-\dfrac{5}{7}\times\left(\dfrac{2}{11}+\dfrac{9}{11}\right)+\dfrac{12}{7}\\ =-\dfrac{5}{7}\times1+\dfrac{12}{7}\\ =1\)

=-5/7 x (2/11 + 9/11 ) + 5/7

=-5/7 x 1 + 5/7

=0

\(\dfrac{-5}{7}\cdot\dfrac{2}{11}+\dfrac{-5}{7}\cdot\dfrac{9}{11}+\dfrac{5}{7}=\dfrac{5}{7}\cdot\dfrac{-2}{11}+\dfrac{5}{7}\cdot\dfrac{-9}{11}+\dfrac{5}{7}\cdot1=\dfrac{5}{7}\cdot\left(\dfrac{-2}{11}+\dfrac{-9}{11}+1\right)=\dfrac{5}{7}\cdot0=\dfrac{0}{7}=0\)

-5/7 x (2/11 + 9/11 ) + 5/7

=-5/7 x 1 + 5/7

=0

\(\frac{-5}{7}.\frac{2}{11}+\frac{-5}{7}.\frac{9}{11}+\frac{5}{7}\)

\(=\frac{-5}{7}\left(\frac{2}{11}+\frac{9}{11}\right)+\frac{5}{7}\)

\(=\frac{-5}{7}.1+\frac{5}{7}\)

\(=\frac{-5}{7}+\frac{5}{7}\)

\(=0\)

-5/7 x (2/11 + 9/11 ) + 5/7

-5/7 x 1 + 5/7

0

\(\frac{5}{7}.\frac{5}{11}+\frac{5}{7}.\frac{2}{11}+\frac{5}{11}.\frac{14}{7}=\left(\frac{5}{7}.\frac{5}{11}\right)+\left(\frac{5}{7}.\frac{2}{11}\right)+\left(\frac{5}{11}.\frac{14}{7}\right)=\frac{25}{77}+\frac{10}{77}+\frac{10}{11}=\frac{5}{11}+\frac{10}{11}=\frac{15}{11}\)

a) 5.(-2)-(-3).(-4)=(-10).(-3).(-4)
=30.(-4)
=-120

b) \(\dfrac{13}{7}-\dfrac{3}{14}=\dfrac{13}{7}+\dfrac{-3}{14}=\dfrac{26}{14}+\dfrac{-3}{14}=\dfrac{23}{14}\)

c) chả biết bạn viết cái j

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