Lời giải:Ta có:
\(\left\{\begin{array}{l} 3 x-y=5 \\ 5 x+2 y=14 \end{array} \Leftrightarrow\left\{\begin{array}{l} y=3 x-5 \\ 5 x+2(3 x-5)=14 \end{array}\right.\right.\)
\(\Leftrightarrow\left\{\begin{array}{l} y=3 x-5 \\ 5 x+6 x-10=14 \end{array} \Leftrightarrow\left\{\begin{array}{l} y=3 x-5 \\ 11 x=24 \end{array} \Leftrightarrow\left\{\begin{array}{l} x=\frac{24}{11} \\ y=3 \cdot\left(\frac{24}{11}\right)-5 \end{array} \Leftrightarrow\left\{\begin{array}{l} x=\frac{24}{11} \\ y=\frac{17}{11} \end{array}\right.\right.\right.\right.\)
Vậy, nghiệm của hệ phương trình là \(\left(\frac{24}{11} ; \frac{17}{11}\right)\).
