the last number is the y-intercept. The y-intercept is 3. Starting at that point, you know that 3/4 is the slope. So count up 3 (rise is 3) and count left 4 (run is 4) to find x. X-intercept would meet at (4,0)
I've added a picture to give you a visual.
If you have any further questions, don't be afraid to reach out! Hope this helps!