Answer:
His book was opened at Page no.296 and Page no.297
Step-by-step explanation:
Let the page number of one page be x
Page number of page facing page no. x = x+1
We are given that the product of the facing pages was 87,912.
So, x(x+1)=87912




(x+297)(x-296)=0
x=296,-297
Since Page no. cannot be negative
So, x=296
x+1=296+1=297
So, his book was opened at Page no.296 and Page no.297
Start with the answer format we want, and work your way toward forming a single fraction like so

Compare that last expression to (2x+1)/(x+2). Notice how the ax and 2x match up, so a = 2 must be the case.
Then we have 2a+b as the remaining portion in the numerator. Plugging in a = 2 leads to 2a+b = 2*2+b = 4+b. Set this equal to the +1 found in (2x+1)/(x+2) to have the terms match.
So, 4+b = 1 leads to b = -3
Therefore, a = 2 and b = -3
------------------------------------------------
An alternative route:

I added and subtracted 4 in the third step so that I could form 2x+4, which then factors to 2(x+2). That way I could cancel out a pair of (x+2) terms toward the very end.
------------------------------------------------
Other alternative methods involve synthetic division or polynomial long division. They are slightly separate but related concepts.
To find a function that represents these values, just substitute x-values in and look for a function that gives you the correct f(x).
A) This works for 0, but not 2
B) This works for 0, 2, and 4 making it the right answer.