SOLUTION: A room contains 96 chairs. The number of chairs per row is four more than the number of rows. Find the number of rows and the number of chairs per row.

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Question 722167: A room contains 96 chairs. The number of chairs per row is four more than the number of rows. Find the number of rows and the number of chairs per row.
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let +r+ = the number of rows
+r+%2B+4+ = the number of chairs /row
+r%2A%28+r+%2B+4+%29+=+96+
+r%5E2+%2B+4r+=+96+
Complete the square
+r%5E2+%2B+4r+%2B+%284%2F2%29%5E2+=+96+%2B+%284%2F2%29%5E2+
+r%5E2+%2B+4r+%2B+4+=+96+%2B+4+
+r%5E2+%2B+4r+%2B+4+=+100+
+%28+r+%2B+2+%29%5E2+=+10%5E2+
take the square root of both sides
+r+%2B+2+=+10+
+r+=+8+
+r+%2B+4+=+12+
The number of rows is 8
The number of chairs /row is 12
Check:
+8+%2A+12+=+96+
OK