$\text { Đáp án: }$
$\text { Theo đề bài, ta có: }$
\(\left[ \begin{array}{l}c=1\\a+b+c=3\\a‐b+c=2\end{array} \right.\)
` => ` \(\left[ \begin{array}{l}c=1\\a+b+1=3\\a-b+1=2\end{array} \right.\)
` => ` \(\left[ \begin{array}{l}c=1\\a+b=2\\a-b=1\end{array} \right.\)
` => ` \(\left[ \begin{array}{l}c=1\\2a=3\\a-b=1\end{array} \right.\)
` => ` \(\left[ \begin{array}{l}c=1\\a=\frac{3}{2}\\a-b=1\end{array} \right.\)
` => ` \(\left[ \begin{array}{l}c=1\\a=\frac{3}{2}\\\frac{3}{2}-b=1\end{array} \right.\)
` => ` \(\left[ \begin{array}{l}c=1\\a=\frac{3}{2}\\b=\frac{1}{2}\end{array} \right.\)
