Răspuns :
4·(1+2+3+...+99) = 200x.
[tex] \frac{4*(99*100)}{2} [/tex] = 2·(99·100).
2·99·100=200x.
99·200=200x.
99·200:200=x.
99=x.
x=99.
[tex] \frac{4*(99*100)}{2} [/tex] = 2·(99·100).
2·99·100=200x.
99·200=200x.
99·200:200=x.
99=x.
x=99.
4·(1+2+3+...+99) = 200x.
\frac{4*(99*100)}{2} = 2·(99·100).
2·99·100=200x.
99·200=200x.
99·200:200=x.
99=x.
x=99.