Question

Tính : A=1/2+1/2 mu 2+1/2 mu 3 +......+1/2 mu 99

GIÚP MÌNH NHA 

Answer 1

\(A=\frac{1}{2}+\frac{1}{2^2}+...+\frac{1}{2^{99}}\)

\(2A=1+\frac{1}{2}+...+\frac{1}{2^{98}}\)

\(2A-A=\left(1+\frac{1}{2}+...+\frac{1}{2^{98}}\right)-\left(\frac{1}{2}+\frac{1}{2^2}+...+\frac{1}{2^{99}}\right)\)

\(A=1-\frac{1}{2^{99}}\)

Answer 2

THANK YOU ! Bn đã giúp mình thoát khỏi cô phù thủy