document.write( "Question 1182609: Lia can rent a van for either $90 per day with unlimited mileage or $50 per day with 250 free miles and an extra $.25 for each mile over 250. for what number of miles traveled in one day with the unlimited mileage plan save Lia money? \n" ); document.write( "
Algebra.Com's Answer #812701 by Theo(13342)![]() ![]() You can put this solution on YOUR website! unlimited plan is 90 dollars a day with no additional mileage charge.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "alternate plan is 50 dollars a day with 250 free miles and an extra .25 per mile for any miles above 250.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the unlimited plan will save money if the alternate plan costs more than 90 dollars total.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "alternate plan starts at 50 dollars with 250 unlimited miles. \n" ); document.write( "any miles over 250 are charge at .25 per mile.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "alternate plan equation is y = 50 + .25 * (x - 250) where x > 250 \n" ); document.write( "this is compare to 90 dollars for the limited plan.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "replace y with 90 to get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "90 = 50 + .25 * (x - 250) \n" ); document.write( "subtract 50 from both sides of the equation to get: \n" ); document.write( "40 = .25 * (x - 250) \n" ); document.write( "divide both sides of the equation by .25 to get: \n" ); document.write( "40/.25 = x - 250 \n" ); document.write( "simplify to get: \n" ); document.write( "160 = x - 250 \n" ); document.write( "add 250 to both sides of the equation to get: \n" ); document.write( "x = 410\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "they should break even when the alternate plan travels 410 miles. \n" ); document.write( "the cost for the alternate plan would be 50 dollars + .25 * (410 - 250) = 50 + .25 * 160 = 50 + 40 = 90.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "any miles traveled over 410 miles in the alternate plan will make it more expensive than the unlimited plan.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "you can see this from the following graph.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " ![]() \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "red is the unlimited plan. \n" ); document.write( "blue is the alternate plan. \n" ); document.write( "coordinate points are in (x,y) format. \n" ); document.write( "x is the number of miles driven. \n" ); document.write( "y is the total cost.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "unlimited plan cost 90 dollars. \n" ); document.write( "alternate plan costs 50 dollars when 250 miles have traveled and 90 dollars when 410 miles have traveled.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "anything over 410 miles and the unlimited plan comes out the winner. \n" ); document.write( " \n" ); document.write( " |