Question 1060752
.
sqrt(1575) =~ 40.


<U>Answer</U>.  35 and 45. The number of seats is 45.




If you want more accurate math solution, here it is.


<pre>
Let the unknown x be the number of rows PLUS 5.

Then the number of seats is (x-5).

According to the condition,  

(x+5)*(x-5) = 1575,

x^2 - 25 = 1575 --->  x^2 = 1575 + 25 = 1600  --->  x = 40.

Then you get the answer.
</pre>

In this way you get the solution of the problem mentally, without using the quadratic formula.



See the lesson

&nbsp;&nbsp;&nbsp;&nbsp;- <A HREF=https://www.algebra.com/algebra/homework/quadratic/lessons/How-to-solve-the-problem-on-quadratic-equation-mentally-and-avoid-boring-calculations.lesson>HOW TO solve the problem on quadratic equation mentally and avoid boring calculations</A> 

in this site.


Also, you have this free of charge online textbook in ALGEBRA-I in this site

&nbsp;&nbsp;&nbsp;&nbsp;- <A HREF=https://www.algebra.com/algebra/homework/quadratic/lessons/ALGEBRA-I-YOUR-ONLINE-TEXTBOOK.lesson>ALGEBRA-I - YOUR ONLINE TEXTBOOK</A>.


The referred lesson is the part of this online textbook under the topic "<U>Quadratic equations</U>".