By looking at where the line intersects the y axis you can find the y-intercept is at (0,4)
Now find the slope by using 2 points on the line. I’ll use (0,4) and (5,6). Use. m=(y2-y1)/(x2-x1). m=(6-4)/(5-0) m=2/5
Now create the equation. y=mx+b
y=(2/5)x+4