Dạng tổng quát của các số hữu tỉ là:

\(\dfrac{9}{25};\dfrac{5}{6};0,36=\dfrac{36}{100}=\dfrac{9}{25}\)

9/25; 5/6; 0,36 = 36/100 = 9/25

a, - \(\dfrac{11}{25}\) = \(\dfrac{-6}{25}\) + \(\dfrac{-5}{25}\) + 

    - \(\dfrac{11}{25}\) =  \(\dfrac{-1}{25}\) + \(\dfrac{-10}{25}\) + 

    - \(\dfrac{11}{25}\) = \(\dfrac{-3}{25}\) + \(\dfrac{-8}{25}\) +  

b, - \(\dfrac{11}{25}\) = \(\dfrac{6}{25}\) - \(\dfrac{17}{25}\)

   - \(\dfrac{11}{25}\) = \(\dfrac{7}{25}\) - \(\dfrac{18}{25}\)

  - \(\dfrac{11}{25}\)  = \(\dfrac{8}{25}\) - \(\dfrac{19}{25}\)

a) \(\frac{1}{2};\frac{-2}{3};\frac{0}{5};\frac{-3}{-8};\frac{4}{-9};....\)

b) \(\frac{a}{b}\)

Trả lời:

a, \(15^8.9^4\)

\(=15^8.\left(3^2\right)^4\)

\(=15^8.3^8\)

\(=45^8\)

b, \(27^2:25^3\)

\(=\left(3^3\right)^2:\left(5^2\right)^3\)

\(=3^6:5^6\)

\(=\left(\frac{3}{5}\right)^6\)

Hok Tốt!!!!

a. 15⁸ . 9⁴

= 15⁸ . (3²)⁴

= 15⁸.3⁸

= (15.3)⁸

= 45⁸

b. 27² : 25³

= (3³)² : (5²)³

= 3⁶ : 5⁶

= \(\left(\frac{3}{5}\right)^6\)

\(\frac{{12}}{{25}} = 0,48;\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\frac{{27}}{2} = 13,5;\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\frac{{10}}{9} = 1,(1)\)

\(\dfrac{12}{25}=\dfrac{12\times4}{25\times4}=\dfrac{48}{100}=0,48\)

\(\dfrac{27}{2}=\dfrac{27\times5}{2\times5}=\dfrac{135}{10}=13,5\)

\(\dfrac{10}{9}=1+\dfrac{1}{9}=1+0,\left(1\right)=1,\left(1\right)=1,111...\)