❏\(\left(\dfrac{3}{4}\right)^x=\dfrac{4^4}{3^4}\)
\(\Rightarrow\left(\dfrac{3}{4}\right)^x=\left(\dfrac{4}{3}\right)^4\)
\(\Rightarrow\left(\dfrac{3}{4}\right)^x=\dfrac{1}{\left(\dfrac{3}{4}\right)^4}\)
\(\Rightarrow x=-4\)
❏\(\left(x-2\right)^8=3\left(x-2\right)^6\)
\(\Rightarrow\left(x-2\right)^2=3\)
\(\Rightarrow x-2=\sqrt{3}\)
\(\Rightarrow x=\sqrt{3}+2\)