document.write( "Question 584744: A TV screen is 40in high and 60in long. Using the vetical and horizontal control buttons, the picture is compressed to 62.5% of its original area, leaving a uniform dark strip around the outside. Find the dimensions of the smaller picture. \n" ); document.write( "
Algebra.Com's Answer #372877 by Theo(13342) You can put this solution on YOUR website! original dimensions are 40 * 60 for an area of 2400 square inches. \n" ); document.write( "the area is reduced to 62.5% of its original area. \n" ); document.write( "this makes the near area equal to .625 * 2400 = 1500. \n" ); document.write( "if we let x equal the height and y equal the length, then we get: \n" ); document.write( "x * y = 1500 \n" ); document.write( "since we know that the length to height ratio is 60/40 = 3/2, we can set the length equal to 3/2 * the height. \n" ); document.write( "since x equals the height and y equals the length, this means that: \n" ); document.write( "y = 3/2 * x \n" ); document.write( "in our equation of x * y = 1500, we replace y with 3/2 * x to get: \n" ); document.write( "x * 3/2 * x = 1500 which simplifies to: \n" ); document.write( "3/2 * x^2 = 1500 \n" ); document.write( "multiply both sides of this equation by 2/3 to get: \n" ); document.write( "x^2 = 1500 * 2/3 which simplifies to: \n" ); document.write( "x^2 = 1000. \n" ); document.write( "solve for x to get x = 31.6227766 \n" ); document.write( "since x = 31.6227766, and y = 3/2 * x, we can solve for y to get: \n" ); document.write( "y = 3/2 * 31.6227766 which is equal to: \n" ); document.write( "y = 47.4341649 \n" ); document.write( "we now have the new dimensions of the screen assuming the same viewing ratio as the original screen. \n" ); document.write( "those new dimensions are: \n" ); document.write( "height = 47.4341649 inches \n" ); document.write( "width = 31.6227766 \n" ); document.write( "the new area is equal to height * width which is equal to: \n" ); document.write( "47.4341649 * 31.6227766 which is equal to 1500 square inches, confirming the calculations are correct. \n" ); document.write( " \n" ); document.write( " |