Respuesta :

We notice that the number of pages read is a function of the number of days:

If y is the # of pages read and x the # days, so the equation becomes:

y = m.x + b where m is the rate of reading or the slope and b a constant. How to calculate m? and later b

Note that we can rewrite the given as:

x|   0   |  2  |  5  |  7  |
-|------|-----|-----|------|
y|  57  | 99|162 |204 |

m= (y₂-y₁)/(x₂-x₁) = Rise/Run 

m= (204-162)/(7-5) = (162-99)/(5-2) = (99-57)/(2-0) = 21

Then 
m = 21 and the function y = 21.x +b

We notice in the table that when x = 0; y = 57, then
57 = 0.x + b that means b = 5 and the final equation is:
y = 21.x + 57