Question

calculați 4 + 6 + 8 +................+ 48 + 50 =?

Answer 1

4+8+10+12+14+16+18+20+22+24+26+28+30+32+34+36+38+40+42+44+46+48+50=648

Answer 2

[tex]4+6+8+...+48+50(dam~factor~comun~pe~doi~pentru~a~forma\\ o~suma~gauss)\\ 2(2+3+4+..+48+50)\\ =\ \textgreater \ 2(1+2+3+4+...+40+50)-1\\ =\ \textgreater \[2 (50*51)]:2-1\\ =\ \textgreater \ 2* 1275-1\\ =\ \textgreater \ S_n=2549 [/tex]