The point (−3, 8) is reflected in the vertical line $x=2$. What are the coordinates of its image?

Reflection in a vertical line leaves the $y$-coordinate unchanged and sends $x$ to $2a-x$, where $x=a$ is the mirror line. The point is 5 units to the left of $x=2$, so the image is 5 units to the right: $x=2+5=7$. The image is (7, 8). Reflecting in the $y$-axis instead would give (3, 8), and reflecting in $y=2$ would give (−3, −4).