Answer:
slope is delta y over delta x. In other words change in y over change in x. so if you take -3 (this is x) and 7 (this is also x) and you find the change. in this example it is positive 10. now you set that number aside and work on y now. so you now take 7 (this is y) and -1 (this is also y) and you find the change. It is -8. Finaly, since slope is delta y over delta x your answer is -8/10. -8/10 is your slope.
Hope this helped!