[tex]\begin{cases} -2x-y=-9 \\ 5x-2y=18 \end{cases}\\\\ \begin{cases} y=-2x+9 \\ 5x-2y=18 \end{cases}\\\\substitution \\\\ 5x-2 \cdot (-2x+9)=18 \\5x+4x-18=18 \\9x-18+18\\9x=36\ \ /:9\\x=\frac{36}{9}\\x=4\\=================\\y=-2x+9 \\y=-2 \cdot 4+9 =-8+9=1\\ \\Answer:\\\\\begin{cases} x=4 \\ y=1 \end{cases}[/tex]
