document.write( "Question 164691: a rectangular building is 25m long and 15m wide. a path of constant width is laid around the whole building. if the area of the path is 90m2.calculate the with of the path to the nearest mm. \n" ); document.write( "
Algebra.Com's Answer #121357 by checkley77(12844)\"\" \"About 
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25*15=375 m^2 is the building area.
\n" ); document.write( "(25+2x)(15+2x)=375+90
\n" ); document.write( "375+50x+30x+4x^2=465
\n" ); document.write( "4x^2+80x+375-465=0
\n" ); document.write( "4x^2+80x-90=0
\n" ); document.write( "\"x=%28-b%2B-sqrt%28b%5E2-4%2Aa%2Ac%29%29%2F%282%2Aa%29\"
\n" ); document.write( "x=(-80+-sqrt[80^2-4*4*-90])/2*4
\n" ); document.write( "x=(-80+-sqrt[6400+1440])/8
\n" ); document.write( "x=(-80+-sqrt[7840]/8
\n" ); document.write( "x=(-80+-88.544)/8
\n" ); document.write( "x=(-80+88.544)/8
\n" ); document.write( "x=8.544/8
\n" ); document.write( "x=1.07 m. is the width of the path.
\n" ); document.write( "Proof:
\n" ); document.write( "(25+2*1.07)(15+2*1.07)=375+90
\n" ); document.write( "(25+2.14)(15+2.14)=465
\n" ); document.write( "27.14*17.14=465
\n" ); document.write( "465~465\r
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