\(64\cdot4^x=16^8\\ \Rightarrow4^3\cdot4^x=\left(4^2\right)^8\\ \Rightarrow4^3\cdot4^x=4^{16}\\ \Rightarrow4^x=4^{16}:4^3\\ \Rightarrow4^x=4^{13}\\ \Rightarrow x=13\)
Vậy `x=13`
64.4x=168
4x=168:64
4x=(42)8:43
4x=416:43
4x=416-3
4x=413
x=13
Vậy x=13