Question

Efectuati urmatoarea suma
Gaus:
2+4+6+.............+50

Answer 1

=2(1+2+3+....+25)=2x25x26:2=650

Answer 2

2+4+6+....+50=
=2(2+4+6+....+50)=
=2x25x(25+1):2=
=2x25x26:2=
=1300:2=
=650