Odpowiedzi

2009-11-27T12:48:12+01:00
1 + 7 + 13 + . . . + (6n − 5) = n(3n − 2)


1 + 7 + 13 + . . . + (6n − 5) + (6n + 2) = n(3n − 2) + (6n + 2)

n(3n − 2) + (6n + 2) = n(3n − 2) + (6n + 2)

(6n + 2) = (6n + 2)
1 5 1