Question

Tìm n\(\in\) N, biết:

\(2^{-1}.2^n+2^n=5.2^n\)

Answer 1

\(2^{-1}.2^n+2^n=5.2^n\\ \Leftrightarrow\dfrac{1}{2}.2^n+2^n-5.2^n=0\\ \Leftrightarrow2^n\left(\dfrac{1}{2}+1-5\right)=0\\ \Leftrightarrow-\dfrac{7}{2}.2^n=0\\ \Leftrightarrow2^n=0\\ \Leftrightarrow n\in\varnothing\)