document.write( "Question 199205: Students of a class are made to stand in rows.If four students are extra in a row there would be two rows less.If four students are less in a row there would be four more rows.Find the number of students in the class? \n" ); document.write( "
Algebra.Com's Answer #149687 by ankor@dixie-net.com(22740)\"\" \"About 
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Students of a class are made to stand in rows. If four students are extra in a
\n" ); document.write( " row there would be two rows less. If four students are less in a row there
\n" ); document.write( " would be four more rows. Find the number of students in the class?
\n" ); document.write( ":
\n" ); document.write( "let s = number students in a row
\n" ); document.write( "let r = number of rows
\n" ); document.write( "then
\n" ); document.write( "No of students = rs
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\n" ); document.write( "\"If four students are extra in a row there would be two rows less.\"
\n" ); document.write( "(r-2)(s+4) = rs
\n" ); document.write( "FOIL
\n" ); document.write( "rs + 4r - 2s - 8 = rs
\n" ); document.write( "rs - rs + 4r - 2s - 8 = 0
\n" ); document.write( "4r - 2s = 8
\n" ); document.write( "2r - s = 4; simplified, divided by 2
\n" ); document.write( ":
\n" ); document.write( "\"If four students are less in a row there would be four more rows.\"
\n" ); document.write( "(r+4)(s-4) = rs
\n" ); document.write( "rs - 4r + 4s - 16 = rs
\n" ); document.write( "rs - rs - 4r + 4s = 16
\n" ); document.write( "-4r + 4s = 16
\n" ); document.write( "-r + s = 4; simplified, divided by 4
\n" ); document.write( ":
\n" ); document.write( "Adding these two equations eliminates s
\n" ); document.write( "2r - s = 4
\n" ); document.write( "-r + s = 4
\n" ); document.write( "-------------
\n" ); document.write( "r = 8 rows
\n" ); document.write( ":
\n" ); document.write( "find s:
\n" ); document.write( "-8 + s = 4
\n" ); document.write( "s = 4 + 8
\n" ); document.write( "s = 12 students in a row
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\n" ); document.write( "Find the number of students in the class?
\n" ); document.write( "8 * 12 = 96 students
\n" ); document.write( ":
\n" ); document.write( ":
\n" ); document.write( "See if that's true
\n" ); document.write( "\"If four students are extra in a row there would be two rows less.\"
\n" ); document.write( "(12+4)*(8-2) =
\n" ); document.write( "16 * 6 = 96
\n" ); document.write( "and
\n" ); document.write( "\"If four students are less in a row there would be four more rows.\"
\n" ); document.write( "(12-4)*(8+4) =
\n" ); document.write( "8 * 12 = 96 \n" ); document.write( "
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