Question

Stie cineva il faca?

Answer 1

Salut,

$\dfrac{10+20+30+\ldots+1000}{5+10+15+\ldots+500}=\dfrac{10\cdot(1+2+3+\ldots+100)}{5\cdot(1+2+3+\ldots+100)}=\\\\\\=\dfrac{10}5=2\in\mathbb{N},\ ceea\ ce\ trebuia\ demonstrat.$

Green eyes.