document.write( "Question 79110: A rectangular garden is to be surrounded by a walkway of constant width. The garden’s dimensions are 30 ft by 40 ft. The total area, garden plus walkway, is to be 1800 ft2. What must be the width of the walkway to the nearest thousandth? \n" ); document.write( "
Algebra.Com's Answer #56777 by checkley75(3666)\"\" \"About 
You can put this solution on YOUR website!
(30+2X)(40+2X)=1800
\n" ); document.write( "1200+80X+60X+4X^2=1800
\n" ); document.write( "4X^2+140X+1200-1800=0
\n" ); document.write( "4X^2+140X-600=0
\n" ); document.write( "X^2+35X-150=0 USING THE QUADRATIC EQUATION WE GET:
\n" ); document.write( "X=(-35+-SQRT[35^2-4*1*-150])/2*1
\n" ); document.write( "X=(-35+-SQRT[1225+600])/2
\n" ); document.write( "X=(-35+-SQRT1825)/2
\n" ); document.write( "X=(-35+-42.72)/2
\n" ); document.write( "X=(-35+42.72)/2
\n" ); document.write( "X=7.72/2
\n" ); document.write( "X=3.86 ANSWER FOR THE BORDER.
\n" ); document.write( "PROOF
\n" ); document.write( "(30+2*3.86)(40+2*3.86)=1800
\n" ); document.write( "(30+7.72)(40+7.72)=1800
\n" ); document.write( "37.72*47.72=1800
\n" ); document.write( "1800=1800\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "
\n" ); document.write( "
\n" );