document.write( "Question 550159: A school community had planned to reduce the number of grade 9 students per class room by constructing additional calss rooms. However, they constructed 4 less rooms than they planned. As the result, the number of students per class was 10 more than they planned. If there are 1200 grade 9 students in the school, determine the current number of class rooms and the number of students per class. \n" ); document.write( "
Algebra.Com's Answer #358486 by stanbon(75887)\"\" \"About 
You can put this solution on YOUR website!
A school community had planned to reduce the number of grade 9 students per class room by constructing additional calss rooms. However, they constructed 4 less rooms than they planned. As the result, the number of students per class was 10 more than they planned. If there are 1200 grade 9 students in the school, determine the current number of class rooms and the number of students per class.
\n" ); document.write( "--------
\n" ); document.write( "Let \"c\" be the original number of classrooms.
\n" ); document.write( "The 1200/c was the original number of students per classroom.
\n" ); document.write( "----
\n" ); document.write( "Equation:
\n" ); document.write( "1200/(c-4) = (1200/c)+10
\n" ); document.write( "Multiply thru by c(c-4)
\n" ); document.write( "---
\n" ); document.write( "1200c = 1200(c-4)+10c(c-4)
\n" ); document.write( "---
\n" ); document.write( "1200c = 1200c-4800 + 10c^2-40c
\n" ); document.write( "----
\n" ); document.write( "10c^2-40c-4800 = 0
\n" ); document.write( "c^2-4c-480 = 0
\n" ); document.write( "Factor:
\n" ); document.write( "(c-24)(c+20) = 0
\n" ); document.write( "---
\n" ); document.write( "Positive solution:
\n" ); document.write( "c = 24 (# of classrooms originaly planned)
\n" ); document.write( "================
\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H.
\n" ); document.write( "================== \n" ); document.write( "
\n" );