Question

tim n biet 2^n+2^n-2=5/2

Answer 1

\(2^n+2^{n-2}=\frac{5}{2}\left(1\right)\)

\(2^n+2^n-2=\frac{5}{2}\)(2)

đề là TH nào trong 2 TH này 

Answer 2

\(2^n+2^{n-2}=\frac{5}{2}\)

\(2^n+2^n:2=\frac{5}{2}\Rightarrow2n\left(1+\frac{1}{2}\right)=\frac{5}{2}\Rightarrow2n=\frac{5}{2}:\frac{3}{2}=\frac{5}{3}\)

\(n=\frac{5}{2}:2=\frac{5}{4}\)

Answer 3

\(2^n+2^n-2=\frac{5}{2}\)

\(\Rightarrow2\left(2^n\right)=\frac{5}{2}+2=\frac{9}{2}\)

\(2^n=\frac{9}{2}:2=\frac{9}{4}\)

.....đến đây thì chịu, chắc là bài lúc trước gửi đúng đề rồi