4x+4x+3=4160
\(\Rightarrow\)4x+4x.43=4160
\(\Rightarrow\)4x.(1+43)=4160
\(\Rightarrow\)4x.65=4160
\(\Rightarrow\)4x=4160:65
\(\Rightarrow\)4x=64
\(\Rightarrow\)4x=43
\(\Rightarrow\)x=3
\(4^x+4^{x+3}=4160\)
\(4^x\left(1+4^3\right)=4160\)
\(\Rightarrow4^x\cdot65=4160\)
\(\Rightarrow4^x=64\)
\(\Rightarrow4^x=4^3\)
\(\Rightarrow x=3\)
Ta làm theo kiểu đặt nhân tử chung nha :
\(4^x+4^{x+3}=4160\)
\(=>4^x\left(1+4^3\right)=4160\)
\(=>4^x.65=4160\)
\(=>4^x=64\)
\(=>x=3\)