You can put this solution on YOUR website!
Ok, so your coordinates are (-2,1) and (1,2).
The equation of the line is y=mx+b
First, find the slope, m.
Now, you have
Now, plug in one of the coordinates in for x and y, and then solve for b (the y-intercept).
And now you have
To check to see if this is correct, sub in x or y of one coordinate and see if you get the other value (sub in x, get the correct y, or sub in y and get the correct x).