document.write( "Question 511524: The length of a rectangle is 3cm longer than twice the width. the area of the rectangle is 90sqcm. Find the length and width of the rectangle \n" ); document.write( "

Algebra.Com's Answer #342244 by oberobic(2304) $\"\"$ $\"About$

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L = 2W +3
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\n" ); document.write( "L*W = 90
\n" ); document.write( "W = 90/L
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\n" ); document.write( "substitute
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\n" ); document.write( "L = 2(90/L) + 3
\n" ); document.write( "L = 180/L + 3
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\n" ); document.write( "L^2 = 180 + 3L
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\n" ); document.write( "L^2 -3L -180 = 0
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\n" ); document.write( "(L-15)(L+12) = 0
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\n" ); document.write( "L = 15 or L = -12
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\n" ); document.write( "Negative length is not possible, so
\n" ); document.write( "L =15.
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\n" ); document.write( "Substitute
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\n" ); document.write( "W = 90/L
\n" ); document.write( "W = 90/15
\n" ); document.write( "W = 6
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\n" ); document.write( "Check the area to be sure of the answer.\r
\n" ); document.write( "\n" ); document.write( "6*15 = 90
\n" ); document.write( "Correct.
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\n" ); document.write( "Answer: Length = 15; width = 6.
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\n" ); document.write( "Done. \n" ); document.write( "

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