How do i graph $y = - 7$?

Hint:In graph to the equation of the form $y = a$ will be a straight line parallel to the x-axis passing through the point $a$ on the y-axis.

Complete step by step solution:
We are given an equation that doesn’t have all the pieces of an equation, here we are only having variable y telling $y = - 7$.
So what we are going to do in this question, we are jumping on the cartesian plane.
There is one most important property of the plane which we have to remember while plotting our equation that graphs to any equation of the form $y = a$ will be straight parallel to the x-axis passing through the point $a$ on the y-axis.
So in our equation given
$
y = - 7 \\
y = ( - 7) \\
y = a \\
$
Where $a$ is equal to $ - 7$
Now plotting a straight line on the cartesian passing through $a$whose value is $ - 7$ on y-axis which is parallel to our x-axis.

Now our graph will be like having line $y = - 7$with green colour.


Hence we’ve successfully plotted our graph of $y = - 7$

Note:1. Cartesian Plane: A Cartesian Plane is given its name by the French mathematician Rene Descartes ,who first used this plane in the field of mathematics .It is defined as the two mutually perpendicular number line , the one which is horizontal is given name x-axis and the one which is vertical is known as y-axis. With the help of these axes we can plot any point on this cartesian plane with the help of an ordered pair of numbers.
2.Draw the cartesian plane only with the help of a straight ruler and pencil to get the perfect and accurate results.