Question

2^30-2^29+2^28-2^27+...-2^3+2^2 

Answer 1

\(A=2^{30}-2^{29}+2^{28}-2^{27}+.............-2^3+2^2\)

\(2A=2^{31}-2^{30}+2^{29}-2^{28}+............-2^4+2^3\)

\(2A+A=2^{31}+2^2\Rightarrow3A=2^{31}+2^2\Rightarrow A=\frac{2^{31}+2^2}{3}\)

Answer 2

sao bằng 2 ^ 31 vậy bạn