document.write( "Question 837711: The perimeter of an airplane ticket is 30 centimeters. The area is 50 square centimeters. What are the dimensions of the ticket? \n" ); document.write( "
Algebra.Com's Answer #504727 by Theo(13342)![]() ![]() You can put this solution on YOUR website! perimeter is equal to 2L + 2W \n" ); document.write( "area is equal to L * W \n" ); document.write( "you get 2 equations: \n" ); document.write( "30 = 2L + 2W \n" ); document.write( "50 = L*W\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "we'll solve by substitution. \n" ); document.write( "you can use either equation to solve for either variable.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "we'll use the second equation to solve for L.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "second equation is: \n" ); document.write( "50 = L*W \n" ); document.write( "divide both sides of this equation by W to get: \n" ); document.write( "L = 50/W\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "we now have a value of L that we can substitute in the first equation which we can then use to solve for W.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the first equation is: \n" ); document.write( "30 = 2L + 2W \n" ); document.write( "replace L with 50/W to get: \n" ); document.write( "30 = 2*(50/W) + 2W \n" ); document.write( "simplify to get: \n" ); document.write( "30 = 100/W + 2W \n" ); document.write( "multiply both sides of this equation by W to get: \n" ); document.write( "30W = 100 + 2W^2 \n" ); document.write( "subtract 30W from both sides of this equation to get: \n" ); document.write( "2W^2 - 30W + 100 = 0 \n" ); document.write( "factor this equation to get: \n" ); document.write( "(2W - 20) * (W - 5) = 0 \n" ); document.write( "solve for W to get: \n" ); document.write( "W = 10 or W = 5\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "if W = 10, then use the equation of 50 = L*W to get L = 5 \n" ); document.write( "if W = 5, then use the equation of 50 = L*W to get L = 10\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "you have 2 possible solutions. \n" ); document.write( "L = 5 and W = 10 or: \n" ); document.write( "L = 10 and W = 5 \n" ); document.write( "both are plausible so we'll test them both out.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "when L = 5 and W = 10: \n" ); document.write( "the first equation becomes 2*5 + 2*10 = 10 + 20 = 30 \n" ); document.write( "the second equation becomes 5*10 = 50 \n" ); document.write( "both equations confirm that the solution of L = 5 and W = 10 is good.\r \n" ); document.write( "\n" ); document.write( "when L = 10 andW = 5: \n" ); document.write( "the first equation becomes 2*10 + 2*5 = 20 + 10 = 30 \n" ); document.write( "the second equation becomes 10*5 = 5 \n" ); document.write( "both equations confirm that the solution of L = 10 and W = 5 is good.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the ticket can have either:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "a length of 5 and a width of 10 or: \n" ); document.write( "a length of 10 and a width of 5.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "since the length is usually longer than the width, you are free to choose that the ticket most likely has a length of 10 and a width of 5.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "alternatively, you can simply say that the dimensions are 5 by 10 and let the recipient of that information determine which is the length and which is the width.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "mathematically, the length can be 10 and the width 5 or the length can be 5 and the width 10. \r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |