Answer
$\color{blue}{y=2}$
Work Step by Step
RECALL:
(1) A line whose equation is of the form $y=k$ is a horizontal line whose y-intercept is $k$. All points on this line have a y-coordinate $y=k$.
(2) Horizontal lines are parallel to each other.
The line we are looking for is parallel to the horizontal line $y=5$.
This means that line is also horizontal and its equation is of the form $y=k$. Every point on the line has a y-coordinate $y=k$.
The line contains the point $(4, 2)$.
Since the y-coordinate of this point is $2$, the equation of the line is:
$\color{blue}{y=2}$