Question

4¹+4²+4³+4⁴+...+4⁵⁰​

Answer 1

Răspuns:

Explicație pas cu pas:

S = 4^1 + 4^2 + 4^3 + 4^4 + ... + 4^50

4S = 4^2 + 4^3 + 4^4 + 4^5 + ...+ 4^51

4S - S = 4^2 + 4^3 + 4^4 + 4^5 + ...+ 4^51 - 4^1 - 4^2 - 4^3 - 4^4 - ... - 4^50

3S = 4^51 - 4

S = 4^51/3 - 4/3