document.write( "Question 379912: The dimensions of Eric’s pool are 9 feet by 7 feet. He wants to build a walkway surrounding the pool so that the square footage of the walkway and pool is 143 square feet. How wide is one side of the walkway? \n" ); document.write( "
Algebra.Com's Answer #269758 by ankor@dixie-net.com(22740)\"\" \"About 
You can put this solution on YOUR website!
The dimensions of Eric’s pool are 9 feet by 7 feet.
\n" ); document.write( " He wants to build a walkway surrounding the pool so that the square footage
\n" ); document.write( " of the walkway and pool is 143 square feet.
\n" ); document.write( " How wide is one side of the walkway?
\n" ); document.write( ":
\n" ); document.write( "Let x = the width of the pool
\n" ); document.write( "Since the walkway goes all the way around the pool the over dimensions will be:
\n" ); document.write( "(2x+9) by (2x+7); then the overall area (pool & walkway) will be:
\n" ); document.write( "(2x+9)*(2x+7) = 143
\n" ); document.write( "FOIL
\n" ); document.write( "4x^2 + 14x + 18x + 63 = 143
\n" ); document.write( ":
\n" ); document.write( "4x^2 + 32x + 63 - 143 = 0
\n" ); document.write( ":
\n" ); document.write( "4x^2 + 32x - 80 = 0; our old friend, the quadratic equation!
\n" ); document.write( "Simplify, divide by 4
\n" ); document.write( "x^2 + 8x - 20 = 0
\n" ); document.write( "Factors to
\n" ); document.write( "(x+10)(x-2) = 0
\n" ); document.write( "The positive solution is what we want here
\n" ); document.write( "x = 2 ft is the width of the walkway
\n" ); document.write( ":
\n" ); document.write( ":
\n" ); document.write( "Check this solution by finding the area with the overall dimensions:
\n" ); document.write( "(4+7) * (4+9) =
\n" ); document.write( "11 * 13 = 143, confirms our solution of x=2
\n" ); document.write( " \n" ); document.write( "
\n" );