Answer :
Since [tex]$L_1$[/tex] is parallel to the [tex]$x$[/tex]-axis, it is a horizontal line. A horizontal line has a constant [tex]$y$[/tex]-coordinate for all values of [tex]$x$[/tex].
Because [tex]$L_1$[/tex] passes through the point [tex]$A(0,4)$[/tex], the constant [tex]$y$[/tex]-coordinate is [tex]$4$[/tex].
Thus, the equation of [tex]$L_1$[/tex] is:
[tex]$$
y = 4
$$[/tex]
Because [tex]$L_1$[/tex] passes through the point [tex]$A(0,4)$[/tex], the constant [tex]$y$[/tex]-coordinate is [tex]$4$[/tex].
Thus, the equation of [tex]$L_1$[/tex] is:
[tex]$$
y = 4
$$[/tex]