Question

Calculați:

( $\frac{2}{10} + \frac{4}{10} + \frac{6}{10} + ... + \frac{20}{10}$ ) - ($\frac{1}{10} + \frac{3}{10} + \frac{5}{10} + ... + \frac{19}{10}$ ) =

Dau coroniță! Mulțumesc!

Answer 1

In fiecare paranteza avem cate 10 termeni.


[tex]\it ( \frac{2}{10} + \frac{4}{10} + \frac{6}{10} + ... + \frac{20}{10} ) - (\frac{1}{10} + \frac{3}{10} + \frac{5}{10} + ... + \frac{19}{10} ) = \\\;\\ = \frac{2-1}{10} +\frac{4-3}{10} + ... +\frac{20- 19}{10} = \frac{1}{10} + \frac{1}{10} +\frac{1}{10} + ... \frac{1}{10} = \frac{10}{10} =1.[/tex]