Răspunsuri

2014-08-27T13:06:10+03:00
Scriem f(1), f(2), ...,f(2012) ca: 2*1-1+2*2-1+....2*2012-1=
=2(1+2+3+...+2012) -2012
=2*((2012*2013)/2) -2012
=2012*2013 -2012
=2012(2013-1)
=2012*2012
=4.048.144