Question

How do you find slope and y intercept of the line on a graph

Answer 1

You find the slope by choosing two points on that graph that the line hits and using the slope formula. 
      y2-y1
m=---------
      x2-x1

You find the y-intercept by looking at where the line hits the y-axis. 

Answer 2

The formula for this is y=mx+b.