Question

Write the equation for the horizontal line going through the
point (3,7).
y =

Answer 1

Answer: y = 7

This is because every point on this horizontal line has a y coordinate of 7.

For instance, the points (0,7) and (3,7) are on this horizontal line. The x coordinate doesn't matter. All that matters is that y is 7. Since x doesn't matter, it's the reason why it doesn't show up in the answer.