Hello, hope you are having a splendid day. :)
Before finding the slope, we have to make sure that our equation is in slope-intercept form.
If you do not know what it is, I will tell you.
It looks like so:
y=mx+b
Where
m is the slope and b is the y-intercept.
For this line, 7 is the slope and -9 is the y-intercept.
Hope it helps. Ask me if you have any queries.
~An emotional teen who helps others with joy
Good luck.