document.write( "Question 765592: the length of a rectangle is 4 feet less than twice its width. If the area of the rectangle is 240 square feet then its dimensions are: \n" ); document.write( "
Algebra.Com's Answer #466271 by 2897696(96)\"\" \"About 
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First make variables for both dimensions
\n" ); document.write( "let x=width
\n" ); document.write( "length= 2x-4
\n" ); document.write( "since finding area is L*W plug in the variables of the dimensions
\n" ); document.write( "so:
\n" ); document.write( "(2x-4)x=240 ==> 2x^2-4x=240
\n" ); document.write( "now put the equation into quadratic form
\n" ); document.write( "so:
\n" ); document.write( "2x^2-2x-240=0 from here factor and find value of x
\n" ); document.write( "factoring: 2(x^2-2x-120)* I undistributed 2
\n" ); document.write( "factor x^2-2x-120=0 ==> (x-12) (x+10)
\n" ); document.write( "now put all the factors together:
\n" ); document.write( "2(x-12)(x+10)=0 solve for x by putting each group of numbers to 0
\n" ); document.write( "2=0 x-12=0 x+10=x
\n" ); document.write( "2=0 is not a solution because, 2 does NOT EQUAL zero
\n" ); document.write( "x+10=0 ==> x=-10
\n" ); document.write( "this is not a solution because there is no such thing as a negative length
\n" ); document.write( "however:
\n" ); document.write( "x-12=0 ==> x=12
\n" ); document.write( " is the solution because 12 is the only possible solution
\n" ); document.write( "now that we have found the width, plug in the values to find length which is
\n" ); document.write( "2x-4 ==> 2(12)-4 ==> 24-4 ==>20 so the length is 20\r
\n" ); document.write( "\n" ); document.write( "ANSWER:
\n" ); document.write( " so the solutions are 12ft and 20ft\r
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