document.write( "Question 211465This question is from textbook Beginning & Intermediate Algebra
\n" ); document.write( ": The length of a rectangle is 7 centimeters less than twice its width. Its area is 30 square centimeters. Find the dimension of the rectangle. \n" ); document.write( "
Algebra.Com's Answer #159815 by RAY100(1637)\"\" \"About 
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Area = Length * Width
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\n" ); document.write( "but L= 2w-7
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\n" ); document.write( "A= (2w-7)*w = 2w^2 -7w also = 30,,,,,given
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\n" ); document.write( "2w^2 -7w -30 =0
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\n" ); document.write( "solve using quadratic formula
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\n" ); document.write( "a=2,,,b=-7,,,,,c=-30
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\n" ); document.write( "w=[-(-7) +/- sqrt{(-7)^2-4(2)(-30)}]/2(2)
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\n" ); document.write( "w= [ 7 +/- sqrt{49+240}]/4
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\n" ); document.write( "w= [ 7 +/-sqrt {289}]/4
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\n" ); document.write( "w= [7 +/- 17]/4
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\n" ); document.write( "w= 6, -2.5 (not reasonable)
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\n" ); document.write( "l=2w-7 = 2*6-7 = 5
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\n" ); document.write( "check, A=5*6 =30,,,,,,ok\r
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