Kayla has already read 45 pages.
Kayla is reading at a rate of 30 pages per day.
John has already read 85 pages.
John is reading at a rate of 10 pages per day.
Their equations can be modeled with

Where m is the slope and b is the y--intercept
Here,
m is the rate at which they are reading per day
b is the amount of pages they have already read
Thus,
A.
Kayla's equation:
m = 30
b = 45
So,

B.
John's equation:
m = 10
b = 85
So,

C.
We need to find the number of days, x, when both have read same amount of pages (which is y). Thus, we equate the expressions for both y's and find x using algebra. Shown below:

After 2 more days, the total number of pages of both Kayla and John would be equal!