document.write( "Question 99587: Construction. A garden area is 30ft long and 20 ft wide. A path of uniform width is set around the edge. If the remaining garden area is 400ft^2, what is teh width of the path? \n" ); document.write( "
Algebra.Com's Answer #72452 by ankor@dixie-net.com(22740)![]() ![]() You can put this solution on YOUR website! A garden area is 30 ft long and 20 ft wide. A path of uniform width is set around the edge. If the remaining garden area is 400 ft^2, what is the width of the path? \n" ); document.write( ": \n" ); document.write( "Draw diagram of this; label the outside dimensions of the rectangle 30 by 20. \n" ); document.write( "Label the width of the path as x, it will be apparent that the dimensions of \n" ); document.write( "the garden (inside the path), will be (30-2x) by (20-2x) \n" ); document.write( ": \n" ); document.write( "The area of the garden is given as 400 sq/ft \n" ); document.write( ": \n" ); document.write( "A simple area equation: \n" ); document.write( ": \n" ); document.write( "length times width = 400 sq/ft \n" ); document.write( "(30-2x) * (20-2x) = 400 \n" ); document.write( ": \n" ); document.write( "FOIL: \n" ); document.write( "600 - 60x - 40x + 4x^2 = 400 \n" ); document.write( "4x^2 - 100x + 600 = 400 \n" ); document.write( "4x^2 - 100x + 600 - 400 = 0 \n" ); document.write( "4x^2 - 100x + 200 = 0; a quadratic equation \n" ); document.write( ": \n" ); document.write( "Simplify, divide by 4 and you have: \n" ); document.write( "x^2 - 25x + 50 = 0 \n" ); document.write( ": \n" ); document.write( "We need to use the quadratic formula to solve this: a=1; b=-25;; c=50 \n" ); document.write( " \n" ); document.write( ": \n" ); document.write( " \n" ); document.write( ": \n" ); document.write( " \n" ); document.write( ": \n" ); document.write( "Two solutions: \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "x = 22.8, not a possible solution, obviously \n" ); document.write( "and \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "x = 2.19 ft is the width of the path \n" ); document.write( ": \n" ); document.write( ": \n" ); document.write( "Check our solution by finding the area of the garden \n" ); document.write( "We have to subtract 2x from the outside dimensions: 2*2.19 = 4.38 \n" ); document.write( ": \n" ); document.write( "(30-4.38) * (20-4.38) = \n" ); document.write( " 25.62 * 15.62 = 400.2 ~ 400 sq/ft \n" ); document.write( " \n" ); document.write( " |