You can find the slope by taking two ordered pairs on the graph , you can use any ordered pairs you like and you can get a right answer but it has to be on the line
for example here I used (2,-1)(0,1) and used the formula os slope y2-y1/x2-x1
1-(-1)/0-2
=2/-2
=-1
Or you can use (3,-2)(-2,3)
3-(-2)/-2-3
=5/-5
=-1
So the slope is -1
Hope this helped