SOLUTION: A rectangular classroom seats 72 students. When the seats are rearranged with three more seats in each row, the classroom has two fewer rows. Find the original number of seats in e

Algebra ->  Quadratic Equations and Parabolas -> SOLUTION: A rectangular classroom seats 72 students. When the seats are rearranged with three more seats in each row, the classroom has two fewer rows. Find the original number of seats in e      Log On


   

Question 892215: A rectangular classroom seats 72 students. When the seats are rearranged with three more seats in each row, the classroom has two fewer rows. Find the original number of seats in each row.
Answer by lwsshak3(11628) About Me  (Show Source):
You can put this solution on YOUR website!
A rectangular classroom seats 72 students. When the seats are rearranged with three more seats in each row, the classroom has two fewer rows. Find the original number of seats in each row.
***
let x=original number of seats in each row.
72%2Fx-72%2F%28x%2B3%29=2
lcd:x(x+3)
72(x+3)-72x=2x(x+3)
72x+216-72x=2x^2+6x
2x^2+6x-216=0
x^2+3x-108=0
(x+12)(x-9)=0
x=-12 (reject)
or
x=9
original number of seats in each row=9