document.write( "Question 213072: a rectangle is 5 ft longer than its width. if the lenght is shortened by 2 ft and the width is increased by 1 ft, the area remains unchanged. find the area. \n" ); document.write( "
Algebra.Com's Answer #160974 by aggie_tutor(13)\"\" \"About 
You can put this solution on YOUR website!
They trick you a little: They are asking for the area, but first you have to solve for the actual width. Fortunately this works out pretty easily. Let width above be w and rectangles A and B.\r
\n" ); document.write( "\n" ); document.write( "Area of rectangle A:
\n" ); document.write( "Width = w
\n" ); document.write( "Length = w + 5
\n" ); document.write( "Area rectangle A: (Length * Widgth) AreaA = (w)*(w+5)\r
\n" ); document.write( "\n" ); document.write( "Area of rectangle B:
\n" ); document.write( "Width = w + 1
\n" ); document.write( "Length = (w + 5) - 2
\n" ); document.write( "Area rectangel B: (Length * Width) AreaB = \"%28w%2B1%29%2A%28w%2B5-2%29+=+%28w%2B1%29%2A%28w%2B3%29\"\r
\n" ); document.write( "\n" ); document.write( "Now the problem says the two areas are equal. Set each area computation equal to the other, and solve for width w. \r
\n" ); document.write( "\n" ); document.write( "AreaA = AreaB
\n" ); document.write( "\"%28w%29%2A%28w%2B5%29+=+%28w%2B1%29%2A%28w%2B3%29\"
\n" ); document.write( "Simplify with distributive property:
\n" ); document.write( "\"%28w%2Aw%29+%2B+%285%2Aw%29+=+%28w%2Aw%29+%2B+%281%2A3%29+%2B+%283%2Aw%29+%2B+%281%2Aw%29\"
\n" ); document.write( "Combine like terms.
\n" ); document.write( "\"w%5E2+%2B+5w+=+w%5E2+%2B+3+%2B+%283w+%2B+w%29\"
\n" ); document.write( "\"w%5E2+%2B+5w+=+w%5E2+%2B+3+%2B+4w\"
\n" ); document.write( "Subtrace the w^2 from each side to get rid of it. The square term cancels itself out, which is really convenient so we don't have to take a root of anything (!).
\n" ); document.write( "\"w%5E2+%2B+5w+%28-w%5E2%29+=+w%5E2+%2B+3+%2B+4w+%28-w%5E2%29\"
\n" ); document.write( "\"5w+=+3+%2B+4w\"
\n" ); document.write( "Subtract 4w from both sides to isolate the number 3.
\n" ); document.write( "\"5w+-+4w+=+3+%2B+4w+%28-+4w%29\"
\n" ); document.write( "\"5w+-+4w+=+3\"
\n" ); document.write( "\"w+=+3\"\r
\n" ); document.write( "\n" ); document.write( "Then plug in w to one of the rectangles to get the area.
\n" ); document.write( "AreaA = Length * Width = \"w+%2A+%28w%2B5%29+=+3+%2A+%283%2B5%29+=+3%2A8+=+24\"\r
\n" ); document.write( "\n" ); document.write( "Check your answer by subbing w in the other rectangle:
\n" ); document.write( "AreaB = Length * Width = \"%28w%2B5-2%29+%2A+%28w%2B1%29+=+%283%2B5-2%29+%2A+%283%2B1%29+=+6%2A4+=+24\"\r
\n" ); document.write( "\n" ); document.write( "AreaA = AreaB !
\n" ); document.write( "
\n" );