[tex]\it I) \ n+n+1=75\Rightarrow 2n=74 \Rightarrow n = 37
\\ \\37+38=75
\\ \\ II) \ n+n+1+n+2=75\Rightarrow 3n=72 \Rightarrow n = 24
\\ \\ 24+25+26=75[/tex]
[tex]\it III) \ n+n+1+n+2+n+3=75\Rightarrow 4n=69\ (nu\ convine) \\ \\ \\ IV)\ n+n+1+n+2+n+3+n+4=75\Rightarrow 5n=65 \Rightarrow n = 13
\\ \\ 13+14+15+16+17=75
\\ \\
V) n+n+1+n+2+n+3+n+4+n+5=75\Rightarrow 6n=60 \Rightarrow n = 10
\\ \\ 10+11+12+13+14+15=75[/tex]
Analog, obținem:
[tex]\it VI)\ 7n=54 \ (nu\ convine)
\\ \\
VII)\ 8n=47 \ (nu\ convine)
\\ \\
VIII)\ 9n=39 \ (nu\ convine)
\\ \\
IX)\ 10n=30 \Rightarrow n=3 \Rightarrow 3+4+5+6+7+8+9+10+11+12=75[/tex]
