
Ryan B. answered 02/11/22
10+ years tutoring Algebra 1
The equation for a horizontal line looks like this: y = c
Here, c is just some number.
For example, y = 4 is a horizontal line. All of the points on this horizontal like have a y-coordinate of 4.
For example, the points (0, 4), (-1, 4), (173892, 4), and (-1/2, 4) all lie somewhere on the horizontal line y = 4.
Given the point (-7, -3), whose y-coordinate is -3, the horizontal line going through this point is y = -3.
The x-coordinate -7 is actually irrelevant in this problem.
I hope this makes sense!