Question

calculati: 3 pe 23+ 6 pe 23 + 9 pe 23 + .....+ 60 pe 23

Answer 1

$\frac{3}{23} (1+2+3+...+20)= \frac{3}{23}*20*21/2= \frac{3}{23} *210= \frac{630}{23}$

Answer 2

[tex]\sf \frac{3}{23}+ \frac{6}{23}+ \frac{9}{23} +........+ \frac{60}{23}= \frac{3+6+9+.....+60}{23} \\ \\ 3+6+9+....+60=3(1+2+3+...+20)=3* \frac{20(20+1)}{2}=3*10*21 \\ \\ = 630 \\ \\ \boxed{\sf Raspuns: \frac{630}{23} }[/tex]