document.write( "Question 482608: The width of a rectangle is 2x + 3 and its length is x + 7. If the area is 40 in^2, what are the dimensions of the Rectangle? \n" ); document.write( "
Algebra.Com's Answer #330419 by ankor@dixie-net.com(22740)\"\" \"About 
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The width of a rectangle is 2x + 3 and its length is x + 7.
\n" ); document.write( " If the area is 40 in^2, what are the dimensions of the Rectangle?
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\n" ); document.write( "We know the area = width * length, therefore
\n" ); document.write( "(2x+3)*(x+7) = 40
\n" ); document.write( "FOIL
\n" ); document.write( "2x^2 + 14x + 3x + 21 = 40
\n" ); document.write( "2x^2 + 17x + 21 - 40 = 0
\n" ); document.write( "2x^2 + 17x - 19 = 0
\n" ); document.write( "You can use the quadratic formula, but this will factor to
\n" ); document.write( "(x-1)(2x+19) = 0
\n" ); document.write( "the positive solution is what we want here
\n" ); document.write( "x = 1
\n" ); document.write( "therefore
\n" ); document.write( "the width: 2(1) + 3 = 5
\n" ); document.write( "the length: 1 + 7 = 8
\n" ); document.write( ":
\n" ); document.write( "Check by finding the area: 5 * 8 = 40
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