Question

cum fac 2*(1+2+3+...+2013)÷2014

Answer 1

Pentru suma  1+2+3+...+2013 ai  formula:
1+2+3+...+2013=$\frac{2013*2014}{2}$

si ai

2*$\frac{2013*2014}{2}$÷2014 = 1

Answer 2

2(1+2+3+....+2013):2014=
=2x2013x2014:2:2014=
=2013(2014:2014)=
=2013x1=2013