$\text { Đáp án: }$
$\text { Ta có: }$
\(\left[ \begin{array}{l}(a+b):2=95\\a:b=4\end{array} \right.\)
$=>$ \(\left[ \begin{array}{l}a+b=95×2\\a=4b\end{array} \right.\)
$=>$ \(\left[ \begin{array}{l}a+b=190\\a=4b\end{array} \right.\)
$=>$ \(\left[ \begin{array}{l}4b+b=190\\a=4b\end{array} \right.\)
$=>$ \(\left[ \begin{array}{l}5b=190\\a=4b\end{array} \right.\)
$=>$ \(\left[ \begin{array}{l}b=190:5\\a=4b\end{array} \right.\)
$=>$ \(\left[ \begin{array}{l}b=38\\a=4b\end{array} \right.\)
$=>$ \(\left[ \begin{array}{l}b=38\\a=4×38\end{array} \right.\)
$=>$ \(\left[ \begin{array}{l}b=38\\a=152\end{array} \right.\)
$\text { Vậy a = 38 và b = 152. }$
