Răspunsuri

2014-08-05T13:05:42+03:00
B=1 +3¹ +3²+3³+3⁴+3⁵....+3⁶⁰ +3⁶¹

B=1+3 +3²(1+3) + 3⁴(1+3)....+3⁶⁰(1+3)

B=4 +3² *4 + 3⁴ *4....+3⁶⁰ *4

B=(3² +3⁴ +....+3⁶⁰) *4  : 4   (trebuiau 3 puncte)
2 3 2
2014-08-05T13:44:10+03:00