2Al+6HCl-->2AlCl3+3H2(1)
x------------------x(133,5x)
Fe+2HCl--->FeCl2+H2(2)
y------------------y(127y)
Theo bài ta có hpt
\(\left\{{}\begin{matrix}27x+56y=13,9\\133,5x+127y=38,75\end{matrix}\right.\Rightarrow\left\{{}\begin{matrix}x=0,1\\y=0,2\end{matrix}\right.\)
%m Al=\(\frac{0,1.27}{13,9}.100\%=19,42\%\)
%m Fe=100-19,42=80,58%