Given the figure in the attached image;
Let us write out the coordinates of point G;
[tex]G=(3,4)[/tex]
If it is reflected about the y-axis, then we have the rule;
[tex](x,y)\rightarrow(-x,y)[/tex]
Applying the rule on point G;
[tex]\begin{gathered} (x,y)\rightarrow(-x,y) \\ G(3,4)\rightarrow G^{\prime}(-3,4) \end{gathered}[/tex]
Therefore, the new coordinates of G will be;
[tex](-3,4)[/tex]
