determinati ultima cifra a numarului a=1+2 supra 2+3 supta 3+...+ 2013 supra 2013

Răspuns :

a=1+2/2+3/3+......+2013/2013
a=1+1+1+.......+1 ( de 2013 ori)
a=2013
u(a)=u(2013)=3
[tex]A = 1 + \frac{2}{2} + \frac{3}{3}+...+\frac{2013}{2013}[/tex]
[tex]A = \underbrace{1 + 1 + 1 + 1 + ... + 1 }_{de\:2013\:ori}[/tex]
[tex]A = 1 \cdot 2013[/tex]
[tex]u(A) = u(2013) = 3[/tex]