1 + 3 + 5 + + .... + 2007

2 câu trả lời

\[\begin{array}{l} 1 + 3 + 5 + ...... + 2007\\ So\,\,cac\,\,so\,\,hang:\,\,\,\frac{{2007 - 1}}{2} + 1 = 1004\\ \Rightarrow 1 + 3 + 5 + ...... + 2007 = \frac{{\left( {2007 + 1} \right).1004}}{2} = 1008016. \end{array}\]

SSH = (2007-1):2+1=1004

Tổng = (1+2007).1004:2=1 008 016