\(E=\dfrac{-1}{3}-\dfrac{2}{3}+\dfrac{2}{5}-\dfrac{3}{5}+\dfrac{1}{5}=-1\)

\(\dfrac{11}{6}+\dfrac{1}{4}=\dfrac{22}{12}+\dfrac{3}{12}=\dfrac{25}{12}\)

\(\dfrac{2}{5}-\dfrac{3}{8}=\dfrac{16}{40}-\dfrac{15}{40}=\dfrac{1}{40}\)

\(\dfrac{3}{10}-\dfrac{4}{15}=\dfrac{9}{30}-\dfrac{8}{30}=\dfrac{1}{30}\)

\(3+\dfrac{2}{5}=\dfrac{15}{5}+\dfrac{2}{5}=\dfrac{17}{5}\)

\(\dfrac{333}{777}+\dfrac{22}{55}=\dfrac{3}{7}+\dfrac{2}{5}=\dfrac{15}{35}+\dfrac{14}{35}=\dfrac{29}{35}\)

1 và 2/3+5/8÷7/2

333^⁷⁷⁷ > 777^333

b, 2^222> 22^22

a) Ta có: 333⁷⁷⁷ = 333^111.7 = (777³)¹¹¹

777³³³ = 777^111.3  = (777³)¹¹¹

Vì 777³<333⁷ nên (777³)¹¹¹ < (777³)¹¹¹

Vậy 333^{777 >} 777³³³

b) Ta có: 2²²² = 2^2.111 =(2¹¹¹)²

22²² = 22^11.2 = (22¹¹)² 

Vì 2¹¹¹ > 22¹¹ nên (2¹¹¹)² > (22¹¹)² 

\(\dfrac{-22}{121}=\dfrac{-22:11}{121:11}=\dfrac{-2}{11}\)

\(\dfrac{4}{-22}=\dfrac{4:2}{-22:2}=\dfrac{2}{-11}=\dfrac{-2}{11}\)

\(-\dfrac{10}{55}=-\dfrac{10:5}{55:5}=-\dfrac{2}{11}=\dfrac{-2}{11}\)

Vậy ...

\(\dfrac{-2}{11}\)

câu a : 

\(\left(x-\dfrac{1}{3}\right)^2-\dfrac{1}{2}=1\dfrac{3}{4}\\ \left(x-\dfrac{1}{3}\right)^2-\dfrac{1}{2}=\dfrac{7}{4}\\ \left(x-\dfrac{1}{3}\right)^2=\dfrac{1}{4}+\dfrac{1}{2}\\ \left(x-\dfrac{1}{3}\right)^2=\dfrac{9}{4}\\ x-\dfrac{1}{3}=\sqrt{\dfrac{9}{4}}\\ x-\dfrac{1}{3}=\dfrac{3}{2}\\ x=\dfrac{3}{2}+\dfrac{1}{3}\\ x=\dfrac{11}{6}\)

câu b : 

\(\dfrac{x-3}{-2}=\dfrac{-8}{x-3}\\ \Rightarrow\left(x-3\right)\cdot\left(x-3\right)=\left(-2\right)\cdot\left(-8\right)\\ \Rightarrow\left(x-3\right)^2=16\\ x-3=\sqrt{16}\\ x-3=4\\ x=4+3\\ x=7\)

câu c : 

\(\dfrac{9}{x}=\dfrac{-35}{105}\\ \Rightarrow\left(-35\right)\cdot x=9\cdot105\\ \left(-35\right)\cdot x=945\\ x=945\div\left(-35\right)\\ x=-27\)

a) \(\dfrac{22}{55}=\dfrac{2}{5}\)

b) \(\dfrac{-63}{81}=\dfrac{-7}{9}\)

c) \(\dfrac{2.14}{7.8}=\dfrac{2.7.2}{7.2.2.2}=\dfrac{1}{2}\)

d) \(\dfrac{49+7.49}{49}=\dfrac{49.\left(7+1\right)}{49}=\dfrac{49.8}{49}=8\)

\(\dfrac{22}{55}=\dfrac{2}{5}\)                                          \(\dfrac{-63}{81}=\dfrac{-7}{9}\)

\(\dfrac{2.14}{7.8}=\dfrac{28}{56}=\dfrac{1}{2}\)                             \(\dfrac{49+7.49}{49}=8\)

a)Ta có:

\(\dfrac{-3}{7}=\dfrac{\left(-3\right)\cdot111}{7.111}=\dfrac{-333}{7}\)

b)\(15\%=\dfrac{3}{20}=0,15\)

\(5\%=\dfrac{1}{20}=0,05\)

c)\(-5\dfrac{1}{2}=-\dfrac{11}{2}\Rightarrow\)số nghịch đảo của nó là:\(-\dfrac{2}{11}\)

\(\)\(1,3=\dfrac{13}{10}\Rightarrow\)số nghịch đảo của nó là:\(\dfrac{10}{13}\)

câu a) = \(\dfrac{-333}{777}\) chứ bạn?

nhân chéo đi

hoặc rút gọn

\(5^5.\dfrac{1}{20}.2^2.3^3:125\)

\(=5^5.\dfrac{1}{2^2.5}.2^2.3^3:5^3\)

\(=\dfrac{2^2.3^3.5^5}{2^2.5^4}=3^3.5=27.5=135\)

= 3125 x 1/20 x 4 x 27 : 125

= 625/4 x 4 x 27 : 125

= 625 x 27 : 125

= 16875 : 125

= 135