The solution is attached in the
image below. I am hoping that this answer has satisfied your query and it will
be able to help you in your endeavor, and if you would like, feel free to ask
another question.
The line of the equation perpendicular to y=5 and cuts through (-5,-7) will be given by
m(x-x1)=y-y1
where m=slope.
from y=0x+5, the slope of the perpendicular line m=0,
thus the equation will be:
0(x--5)=y--7
0=y+7
y=-7
The equation is y=-7