document.write( "Question 332644: The area of a rectangle is 21 square meters. Find the length and width of the rectangle if its length is 4 meters greater than its width. Use an equation and the formula for the Area of a rectangle = (width)(length). \n" ); document.write( "
Algebra.Com's Answer #238368 by benazir.sj@gmail.com(109)\"\" \"About 
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Let us assume the width as x so and length as 4+x
\n" ); document.write( "given area =21 sqm
\n" ); document.write( " area =length *width
\n" ); document.write( "21= (4+x)* x
\n" ); document.write( "21=4x+x^2
\n" ); document.write( "we can change this eqaution into standard form
\n" ); document.write( "x^2+4x-21=0
\n" ); document.write( "now factor this eqaution
\n" ); document.write( "x^2+4x-21=0
\n" ); document.write( "x^2+7x-3x-21=0
\n" ); document.write( "x(x+7)-3(x+7)
\n" ); document.write( "(x-3)(x+7)=0
\n" ); document.write( "x=3,-7
\n" ); document.write( "since wehave to calculte the area we have to consider only the positive value of x
\n" ); document.write( "x=3\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "checking
\n" ); document.write( "x=3
\n" ); document.write( "21=(x+4)*x
\n" ); document.write( "21 =3+4*3
\n" ); document.write( "21=7*3
\n" ); document.write( "21=21
\n" ); document.write( "x=-7
\n" ); document.write( "21 =(-7+4)*3
\n" ); document.write( "21 =-3*3
\n" ); document.write( "21 notequal to -9 \n" ); document.write( "
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