document.write( "Question 1205745: Trashia left Riverside, California, driving her motorhome north on Interstate 15 towards Salt Lake City at a speed of 40 miles per hour. Half an hour later, Karissa left Riverside in her car on the same route as Trashia, driving 60 miles per hour. Solve the system:\r
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document.write( "{(40 y=60 x),(y=x+1/2) :}\r
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document.write( "A. for x to find out how long it will take Karissa to
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document.write( "catch up to Trashia.\r
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document.write( "B. What is the value of y the number of hours
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document.write( "Trashia will have driven before Karissa catches up
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document.write( "to her? \n" );
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Algebra.Com's Answer #842750 by Theo(13342)![]() ![]() You can put this solution on YOUR website! your two equations that you show that need to be solved simultaneously are:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "40y = 60x \n" ); document.write( "y = x + 1/2\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "in the first equation, replace y with x + 1/2 from the second equation to get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "40 * (x + 1/2) = 60 * x \n" ); document.write( "simplify to get: \n" ); document.write( "40 * x + 40 * 1/2 = 60 * x \n" ); document.write( "simplify further to get: \n" ); document.write( "40 * x + 20 = 60 * x \n" ); document.write( "subtract 40 * x from both sides of the equation to get: \n" ); document.write( "20 = 60 * x - 40 * x \n" ); document.write( "combine like terms to get: \n" ); document.write( "20 = 20 * x \n" ); document.write( "solve for x to get: \n" ); document.write( "x = 1\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "go back to your original two equations and replace x with 1.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "you get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "40y = 60x becomes 40y = 60 * 1 \n" ); document.write( "simplify to get 40y = 60 \n" ); document.write( "divide both sides of the equation by 40 to get: \n" ); document.write( "y = 60/40 = 1.5\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "y = x + 1/2 \n" ); document.write( "replace x with 1 to get: \n" ); document.write( "y = 1 + 1/2 \n" ); document.write( "combine like terms to get: \n" ); document.write( "y = 1.5.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "both equations get y = 1.5\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "your solution is x = 1 and y = 1.5\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "answers to your questions are:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "A. for x to find out how long it will take Karissa to \n" ); document.write( "catch up to Trashia.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "trashia was traveling at 40 miles per hour. \n" ); document.write( "karissa was traveling at 60 miles per hour.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "y is the time that trashia was driving. \n" ); document.write( "x is the time that karissa was driving.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "since y = 1.5, then trashia was traveling for 1.5 hours at 40 miles per hour for a distance of 60 miles.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "since x = 1, then karissa was traveling for 1 hour at 60 miles per hour for a distance of 60 miles.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "karissa caught up to trashia at the 60 mile mark.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "it took karissa 1 hour to catch up to trashia.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "B. What is the value of y the number of hours \n" ); document.write( "Trashia will have driven before Karissa catches up \n" ); document.write( "to her?\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "y is equal to 1.5 hours. \n" ); document.write( "x is equal to 1 hour.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "trashia was driving for 1.5 hours before karissa caught up to her.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "i usually solve problems like these as follows:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the basic formula is rate * time = distance.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "for trashia, the formula becomes 40 * y = d \n" ); document.write( "40 is the rate, y is the time, d is the distance.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "for karissa, the formula becomes 60 * x = d \n" ); document.write( "60 is the rate, x is the tie, d is the distance.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "you are then given tht y = x + 1/2.\\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the two formulas become: \n" ); document.write( "40 * (x + 1/2) = d \n" ); document.write( "60 * x = d\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "since they are both equal to d, you can set the expressions on the left side of each equation equal to each other to get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "40 * (x + 1/2) = 60 * x \n" ); document.write( "simplify to get: \n" ); document.write( "40 * x + 20 = 60 * x \n" ); document.write( "subtract 40 * x from both sides of the equation to get: \n" ); document.write( "20 = 20 * x \n" ); document.write( "solve for x to get: \n" ); document.write( "x = 1 \n" ); document.write( "since y = x + 1/2, you get y = 1.5\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "i only mentioned all this to let you know that you were dealing with a basic rate * time = distance type formula.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "if you find that informative, fine. \n" ); document.write( "if not, distregard.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "any additional questions or concerns regarding this problem can be addressed to me. \n" ); document.write( "theo\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( " |