👤
RobertaRadu
a fost răspuns

cum se rezolva ex de genul. 2+4+6+...+2016 si 1+3+5+...+225 ? help plz urgeeeent

Răspuns :

2+4+6+...2016=DAM PE 2 FACTOR COMUN

2(1+2+3+...1008)=
2X(1008X1009):2=
1008X1009=1017072

1+3+5+...225=
1+1+2+2+3+3+4+....112+113=
(1+2+3+4+..112)+(1+2+3+,....113)=
(112X113):2+(113X114):2=
12656:2+12882:2=
6328+6441=
12769