To find the slope of a line, you can use some basic methods. The one I'm about to show you is the easiest for me to understand. But, let's first lay down the meaning of slope. Slope is basically a change in y over x, in a fraction form.
Example: y/x
In your problem, you have the coordinates (3, 0) and (4, 1). With these, I'll show you how to find the slope. First though, look at your numbers on the right of each coordinate. Those are your "y", and the left is your "x".
You need to look at them and think, "How many times does this number go into this number?" Look at it this way:
How many times can 3 go into 4?
3 + 1 = 4
One time.
How many times can 0 go into 1?
0 + 1 = 1
One time.
So, your slope will be (1, 1) or 1/ 1