Răspunsuri

  • Utilizator Brainly
2014-02-26T10:38:15+02:00
Fie a1, a2,..., a20 ∈N
0,60(5)= \frac{605-60}{900}= \frac{545}{900}= \frac{109}{180}
Din enunt:
 \frac{ a_{1}}{ \frac{1}{0,60(5)} }=....= \frac{ a_{20} }{ \frac{1}{0,5} }=k=> \frac{109 a_{1} }{180}=... \frac{ a_{20} }{2}=k=>k=109=>
 a_{1}=180,... ,a_{20}=218
Deoarece k=109 rezulta ca a1, a2, ..., a20 sunt pare si vom avea:
a_{1} + a_{2} +...+ a_{20}=180+182+...+218=10*(180+218)=3980