Question 388650
Let {{{132/x}}} be the price of each book. We have


{{{(x-1)(132/x + 1) = 132}}}


Expanding the left hand side,


{{{132 + x - 132/x - 1 = 132}}}


{{{x - 132/x = 1}}}


{{{x^2 - x - 132 = 0}}}


{{{(x - 12)(x + 11) = 0}}}


{{{x = 12}}} (take the positive value)