👤

Am adunat un nr.cu dublul sau,la suma obtinuta am adaugat 2000,din noua suma am scazut 3999,apoi am scazut inca 101,obtinand astfel 900.Care este numarul initial?

Răspuns :

(ax3+2000)-3999-101=900/+101
(ax3+2000)-3999=1001/+3999
(ax3+2000)=5000/-2000
ax3=3000/3
a=1000
{[(a+2a)+2000]-3999}-101=900
[(a+2a)+2000]-3999=1001
(a+2a)+2000=5000
3a+2000=5000
3a=3000
a=3000:3
a=1000