Question 262173: The product of the page numbers on two facing pages of a book is 156. Find the page numbers. Found 2 solutions by texttutoring, richwmiller:Answer by texttutoring(324) (Show Source):
You can put this solution on YOUR website! The pages are facing each other, so they are consecutive numbers:
Let x = the first page number
y = the second page number
The second page number is just 1 more than the first, because they are consecutive numbers:
x+1 = y
We also know that the products of the numbers is equal to 156:
xy = 156
Now we will sub y = x+1 into the second equation:
x(x+1) = 156
x^2 + x = 156
x^2 + x - 156 = 0
Factoring (or using the quadratic formula) gives us:
(x+13)(x-12) = 0
x = - 13, or x = 12.
A page number can't be negative, so we will choose x=12.
This means that the second page must be page 13.
So the first page is 12, and the facing page is 13.
You can put this solution on YOUR website! This problem has come up several times very recently.
n*(n+!)=156
n^2+n-156=0
(n-12)(n+13)=0
n=12
n=-13
page numbers can't be negative
so start with 12
12*13=156
