Question

2^2+2^3+2^4+2^5+...+2^15

Answer 1

\(A=2^2+2^3+...+2^{15}\)

\(\Leftrightarrow2A=2^3+2^4+...+2^{16}\)

\(\Leftrightarrow A=2^{16}-4\)

Answer 2

\(\text{Đặt }A=2^2+2^3+2^4+2^5+...+2^{15}.\)

      \(\Rightarrow2A=2^3+2^4+2^5+...+2^{16}.\)

      \(\Rightarrow A=2^{16}-4.\)