Question

Tìm x biết:

x + (x+1) + (x+2) + (x+3) +...+ (x+2012) = 2012.2013

Answer 1

Ta có : x + (x + 1) + (x + 2) + .... + (x + 2012) = 2012.2013

<=> (x + x + x + ..... + x) + (1 + 2 + .... + 2012)  = 2012.2013

<=> 2013x + \(\frac{2012.2013}{2}\) = 2012.2013

<=> 2013x = 2012.2013 - \(\frac{2012.2013}{2}\)

<=> 2013x = 2025078