Notice that the reflection is over a line of the form x=constant; in this case, the y-coordinate of the reflected point stays the same while the x-coordinate changes as expressed by the transformation below
[tex]\begin{gathered} y\rightarrow y \\ x\rightarrow2a+x \\ where \\ x=a\rightarrow\text{ vertical line} \end{gathered}[/tex]Hence, in our case
[tex]\Rightarrow(x,y)=(2*-4-x,y)=(-8-x,y)[/tex]Transform points N, M, and O accordingly,
[tex]\begin{gathered} \Rightarrow N^{\prime}=(-8-(-5),2)=(-8+5,2)=(-3,2) \\ \Rightarrow M^{\prime}=(-8-(-2),1)=(-6,1) \\ \Rightarrow O^{\prime}=(-8-(-3),3)=(-5,3) \end{gathered}[/tex]