since the page numbers are consecutive numbers, this means that one number is odd and one number is even and one is 1 more than the other.
lets say we have 2 numbers x and y that are consecutive.
y = x + 1
so the product is x*y=506
or x*(x+1) = 506 | x^2 + x = 506
x^2 + x -506 = 0
this is a quadratic equation which can be easily solved by a quadratic formula or can be factored into following.
using the distributive property we have x = -23 and +22
x = -23 is an admissible so we will ignore it.
therefore x = 22
since y = x +1, y = 23
Therefore, the two numbers on the facing pages are 22 and 23.
you can check wheather or not you are right:
22 * 23 is indeed 506 so yes!! our solution is correct.
Note: ofcourse u could have guessed as well to get the answer but it will not get you the marks.