Question

Calculați sumele:
b) S= +1-2+3-4+5-6+7- 8-...+2011-2012;​

Answer 1

Răspuns:

$S=+1-2+3-4+5-6+7-8+...+2011-2012 =?$

$(+1)-2 =-1$

$-1*($  $\frac{2012}{2}$ $)$$= -1*(+1006)$ $=-1006$

$S= +1-2+3-4+5-6+7- 8-...+2011-2012 =-1006$