Question

\(\dfrac{103}{105}và\dfrac{205}{208}\)

So sánh bằng cách thuận tiện nhất nhé

 

Answer 1

Ta có:

+) \(\dfrac{103}{105}=\dfrac{105}{105}-\dfrac{2}{105}=1-\dfrac{2}{105}=1-\dfrac{6}{315}\)

+) \(\dfrac{205}{208}=\dfrac{208}{208}-\dfrac{3}{208}=1-\dfrac{3}{208}=1-\dfrac{6}{416}\)

Vì \(\dfrac{6}{315}>\dfrac{6}{416}\) nên \(1-\dfrac{6}{315}< 1-\dfrac{6}{416}\) hay \(\dfrac{103}{105}< \dfrac{205}{208}\)

 

 

 

Answer 2

Ta có:

\(\left\{{}\begin{matrix}1-\dfrac{103}{105}=\dfrac{2}{105}\\1-\dfrac{105}{208}=\dfrac{2}{208}\end{matrix}\right.\)

Vì \(105< 208\Rightarrow\dfrac{2}{105}>\dfrac{2}{208}\Rightarrow\dfrac{103}{105}< \dfrac{203}{208}\)