Answer
$y=-7$
Work Step by Step
RECALL:
The slope-intercept form of a line's equation is $y=mx+b$ where $m$ = slope and $b$ = y-intercept.
With $m=0$, the tentative equation of the line is $y=0x+b$.
To find the value of $b$, substitute the x and y coordinates of the given point to have:
$y = 0x+b
\\-7=0(-5)+b
\\-7=0+b
\\-7=b$
Thus, the equation of the line in slope-intercept form is:
$y=0x + (-7)
\\y=-7$