Răspuns:
Explicație pas cu pas:
In suma sunt 102 termeni, 102 se imparte la 2 si la 3
Pt. 7 , grupam cate 2:
A =1+6 + 6^2(1+6) + 6^4(1+6) +...+6^100(1+6) =
7(1+ 6^2 + 6^4 +...+6^100)
Pt. 37, grupam cate 2 , dar alternat :
A = 1 +6 + 6^2 +6^3 +6^4 +6^5 +6^6 +6^7...+6^100 +6^102
1 +6^2, 6+6^3, 6^2 +6^4, ..., 6^99 +6^102
A = 1 +6^2+ 6(1 +6^2) + 6^2(1 +6^2), ..., 6^99(1 +6^2) =
37(1 +6 +6^2 + 6^99)
Pt. 43, grupam cate 3:
A = 1+6+6^2 + 6^3(1+6+6^2) + ...+6^99(1+6+6^2) =
43(1 + 6^3 +... +6^99)