p=75n+250
slope intercept form is y=mx+b
The difference between 4-6 is 150
150/2 = 75
So the slope (or m) is 75
y=75x+b
For finding the starting pay (or b)
550-4m= b
550-4(75) = b
550-300 = b
250 = b
So the starting pay(or y-intercept) is 250
y = 75x+250
Change y and x to your variables
p=75n+250 is your answer :)