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) 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 = \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( " \n" ); document.write( "Simplify with distributive property: \n" ); document.write( " \n" ); document.write( "Combine like terms. \n" ); document.write( " \n" ); document.write( " \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( " \n" ); document.write( " \n" ); document.write( "Subtract 4w from both sides to isolate the number 3. \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \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 = \n" ); document.write( "\n" ); document.write( "Check your answer by subbing w in the other rectangle: \n" ); document.write( "AreaB = Length * Width = \n" ); document.write( "\n" ); document.write( "AreaA = AreaB ! \n" ); document.write( " |