document.write( "Question 238378: Hi,
\n" ); document.write( "Can you please help me with this problem?
\n" ); document.write( "Find the dimensions of a rectangle whose perimeter is 46m and whose area is 126m.
\n" ); document.write( " Also
\n" ); document.write( "The length of a rectangle is 8 cm greater then its width. Find the dimensions if its area is 105 cm
\n" ); document.write( "We need to solve it using quadratics and possibly using factoring!
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Algebra.Com's Answer #175339 by ankor@dixie-net.com(22740)\"\" \"About 
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Find the dimensions of a rectangle whose perimeter is 46m and whose area is 126m.
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\n" ); document.write( "The perimeter equation:
\n" ); document.write( "2L + 2W = 126
\n" ); document.write( "Simplify divide by 2
\n" ); document.write( "L + W = 23
\n" ); document.write( "W = (23-L); use for substitution
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\n" ); document.write( "The area
\n" ); document.write( "L * W = 126
\n" ); document.write( "Substitute (23-L) for W
\n" ); document.write( "L*(23-L) = 126
\n" ); document.write( "23L - L^2 = 126
\n" ); document.write( "Arrange as a quadratic equation
\n" ); document.write( "-L^2 + 23L - 126 = 0
\n" ); document.write( "Multiply by -1, easier to factor:
\n" ); document.write( "L^2 - 23L + 126 = 0
\n" ); document.write( "Factors to
\n" ); document.write( "(L-9)(L-14) = 0
\n" ); document.write( "Two solutions
\n" ); document.write( "L = 9, then W = 14
\n" ); document.write( "or
\n" ); document.write( "L = 14. then W = 9
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\n" ); document.write( "Check: 2(14)+2(9) = 46
\n" ); document.write( "and area: 14 * 9 = 126
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\n" ); document.write( "The length of a rectangle is 8 cm greater then its width. Find the dimensions if its area is 105 cm
\n" ); document.write( ":
\n" ); document.write( "Let x = the width
\n" ); document.write( "then
\n" ); document.write( "(x+8) = the length
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\n" ); document.write( "Area
\n" ); document.write( "x(x+8) = 105
\n" ); document.write( "x^2 + 8x - 105 = 0; our old friend, the quadratic equation!
\n" ); document.write( "factors to
\n" ); document.write( "(x+15)(x-7) = 0
\n" ); document.write( "The positive solution is what we want here
\n" ); document.write( "x = 7 cm, the width
\n" ); document.write( "then
\n" ); document.write( "7 + 8 = 15 cm; the length
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\n" ); document.write( "It this true?: 7 * 15 = 105 sq cm
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