yearbook printer charges based on the number of pages printed. Here is a table that shows the cost of some recent yearbooks.
Number of pages 50 100 150 200
Cost 1.55 2.25 2.95 3.65
Which equation gives the cost, y, in terms of the number of pages, x?
A.

y = 0.014x + 49.15

B.

y = 0.014x + 1.55

C.

y = 0.014x + 0.85

D.

y = 58.8x + 0.85

Question

yearbook printer charges based on the number of pages printed. Here is a table that shows the cost of some recent yearbooks.
Number of pages  50  100  150  200 
Cost  1.55  2.25  2.95  3.65 
Which equation gives the cost, y, in terms of the number of pages, x?
A. 
 
y = 0.014x + 49.15
   
   

 

 
  

  B. 
 
y = 0.014x + 1.55
   
   

 

 
  

  C. 
 
y = 0.014x + 0.85
   
   

 

 
  

  D. 
 
y = 58.8x + 0.85

kirbykirby · Answer

You can first find the slope of the line by taking two points $(x_1, y_1)$ and $(x_2, y_2)$, and apply the formula:
$$\text{slope}=m=\frac{y_2-y_1}{x_2-x_1} $$
This $m$ is the one in the equation of the line $y=mx+b$

Now to find $b$, you can substitute any coordinate that you have in your table. That is, substitute $y $ and $x$ into the equation of the line (with the value of $m$ plugged in\) which will allow you to solve for $b$