Question

Help....................

Answer 1

Răspuns

1015056

Explicație pas cu pas:

$S=\frac{(u+p)*n}{2}\\\\n=\frac{u-p}{r}+1$

u=ultimul termen al sumei

p=primul termen al sumei

n=numarul de termeni

r=ratia/ din cat in cat sunt (ex: 1,3,5 ⇒ r=2)

$S=\frac{(2015-1)*1008}{`2}=\frac{2014*1008}{2}=1007*1008=1015056\\\\n=\frac{2015-1}{2}+1=\frac{2014}{2}+1=1007+1=1008$