A rectangular auditorium seats 1144 people. The number of seats in each row exceeds the number of rows by 18. Find the number of seats in each row.

44 seats in each row

Problem:

A rectangular auditorium seats 1144 people. The number of seats in each row exceeds the number of rows by 18. Find the number of seats in each row.

Step-by-step explanation:

Let n be the number of rows.

If the number of seats exceed the number of rows by 18, then the number ot seats can be represented by n+18.

So we have a n by n+18 rectangle whose number of seats in all is 1144.

So we need to solve n(n+18)=1144

Distribute: n^2+18n=1144

Subtract 1144 on both sides" n^2+18n-1144=0

What two numbers multiply to be -1144 but also add to be 18?

Hmmm.. let's break -1144 down a little into smaller factors.

-1144=2(-572)=4(-286)=8(-143)=-8(13)(11)=-26(44)

We found a pair of factors that will work? -26 and 44.

So the factorization of our quadratic equation is (n-26)(n+44)=0.

This implies either n-26=0 or n+44=0 .

n=26 by adding 26 on both sides for first equation.

n=-44 by subtracting 44 on both sides for second equation.

n=26 is the only one that works.

This means there are 26 rows and 26+18 seats in each row.

26 rows

44 seats in each row

That product does equal 1144 seats in all.

maybe i can