Let's use the following property:
[tex]x^y\cdot x^z=x^{y+z}[/tex][tex]\begin{gathered} f(x)=4\cdot2^{2x} \\ g(x)=2^{4x+2}=2^{4x}\cdot2^2=4\cdot2^{4x} \\ h(x)=4^{2x+1}=4^{2x}\cdot2^{1^{}}=2\cdot4^{2x} \\ \text{Therefore:} \\ \text{None of them are equivalent} \end{gathered}[/tex]