[tex] \frac{ \sqrt{1} - \sqrt{2} }{ \sqrt{1 \times 2} } = ( \frac{1}{ \sqrt{1} } - \frac{1}{ \sqrt{2} } ) \times ( - 1)[/tex]
Asa se pot scrie toate pana la ultima. Dai (-1) factor comun
[tex]( - 1) \times ( \frac{1}{ \sqrt{1} } - \frac{1}{ \sqrt{2} } + \frac{1}{ \sqrt{2} } - \frac{1}{ \sqrt{3} } + ... \frac{1}{ \sqrt{99} } - \frac{1}{ \sqrt{100} } )[/tex]
In paranteza raman doar primul si ultimul termen, ceilalti se reduc cate 2.
