Question

REZOLVATI ECUATIA:
2(1+3+3²+...+3¹⁸)+1=n¹⁹

Answer 1

Salut,

S=1+3+3²+...+3¹⁸, deci enunțul ar fi 2S + 1 = n¹⁹

3S=3+3²+...+3¹⁸+3¹⁹ => 3S - S = 3¹⁹ - 1, deci 2S = 3¹⁹ - 1 => 2S + 1 = 3¹⁹ = n¹⁹, deci n = 3.

Green eyes.