tl;dr: The slope is -5/2.
Hello!
First, if you get graphing paper and place those points, you'll see that the line is going down instead of up. This tells us that the slope is negative.
Now, we use the rise/run strategy.
Doing so, we are given 5/2. Since this is a negative, the slope will actually be -5/2.
So, the slope is -5/2.
Hope this was helpful. Please, correct me if I got something incorrect. Have a great day!