\(2^x=16\Rightarrow x=4\)
\(3^{x+1}=9^x\Rightarrow3^{x+1}=3^{2x}\Rightarrow x+1=2x\Rightarrow x=1\)
\(2^{x-1}=8^5\Rightarrow2^{x-1}=2^{15}\Rightarrow x-1=15\Rightarrow x=16\)
\(\left\{{}\begin{matrix}7x=3y\\y-x=16\end{matrix}\right.\Rightarrow\left\{{}\begin{matrix}y=\dfrac{7x}{3}\\\dfrac{7x}{3}-x=16\end{matrix}\right.\) \(\Rightarrow\left\{{}\begin{matrix}y=28\\x=12\end{matrix}\right.\)
\(\left\{{}\begin{matrix}\dfrac{2x}{5y}=-\dfrac{1}{6}\\2x-5y=14\end{matrix}\right.\Rightarrow\left\{{}\begin{matrix}5y=-12x\\2x+12x=14\end{matrix}\right.\) \(\Rightarrow\left\{{}\begin{matrix}y=-\dfrac{12}{5}\\x=1\end{matrix}\right.\)
\(\dfrac{x}{3}=\dfrac{y}{4}=\dfrac{z}{7}=\dfrac{x+y}{7}=\dfrac{14}{7}=2\Rightarrow x=6;y=8;z=14\)
