Question

Tìm x :

\(4^x+4^{x+3}=4160\)

Answer 1

4^x+4^x+3=4160

=>4^x+4^x.4³=4160

=>4^x(1+64)=4160

=>65.4^x=4160

=>4^x=64

=>x=3

Vậy x=3

Answer 2

\(4^x+4^{x+3}=4160\)

\(\Rightarrow4^x+4^x.4^3=4160\)

\(\Rightarrow4^x.\left(1+4^3\right)=4160\)

\(\Rightarrow4^x.65=4160\)

\(\Rightarrow4^x=64\)

\(\Rightarrow x=3\)

Answer 3

\(4^x+4^x.4^3=4160\)

\(\Leftrightarrow4^x\left(1+64\right)=4160\)

\(\Leftrightarrow4^x=4160:65\)

\(\Leftrightarrow4^x=64=4^3\)

\(\Leftrightarrow x=3\)