$\text { Đáp án: }$

$\text { Ta có: }$

\(\left[ \begin{array}{l}(a+b):2=95\\a:b=4\end{array} \right.\)

$=>$ \(\left[ \begin{array}{l}a+b=95×2\\a=4b\end{array} \right.\) 

$=>$ \(\left[ \begin{array}{l}a+b=190\\a=4b\end{array} \right.\) 

$=>$ \(\left[ \begin{array}{l}4b+b=190\\a=4b\end{array} \right.\) 

$=>$ \(\left[ \begin{array}{l}5b=190\\a=4b\end{array} \right.\) 

$=>$ \(\left[ \begin{array}{l}b=190:5\\a=4b\end{array} \right.\) 

$=>$ \(\left[ \begin{array}{l}b=38\\a=4b\end{array} \right.\) 

$=>$ \(\left[ \begin{array}{l}b=38\\a=4×38\end{array} \right.\) 

$=>$ \(\left[ \begin{array}{l}b=38\\a=152\end{array} \right.\) 

$\text { Vậy a = 38 và b = 152. }$

( a + b ) : 2 = 95

a+ b = 95 x 2

a + b = 190

a:b = 4

a : b = 4 x 4

a : b = 16

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