Substitute second expression (x=y) in the first expression.
[tex]\begin{gathered} -10x+4y=-18 \\ -10\times y+4y=-18 \\ -6y=-18 \\ y=\frac{-18}{-6} \\ y=3 \end{gathered}[/tex]Substitute the above value of y in the expression number 2.
[tex]\begin{gathered} x=y \\ x=3 \end{gathered}[/tex]Thus, the value of x=3 and the value of y=3.