document.write( "Question 1196710: what is an ordered pair for 5x - 2y = 12 and -5x + 6y = -56
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Algebra.Com's Answer #829773 by math_tutor2020(3816)![]() ![]() ![]() You can put this solution on YOUR website! \n" ); document.write( "Given System of Equations \n" ); document.write( "5x-2y = 12 \n" ); document.write( "-5x+6y = -56\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Add the equations straight down \n" ); document.write( "The x terms cancel out (since 5x+(-5x) = 0x = 0) \n" ); document.write( "The y terms combine to 4y \n" ); document.write( "The right hand sides combine to -44\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Therefore, \n" ); document.write( "4y = -44 \n" ); document.write( "y = -44/4 \n" ); document.write( "y = -11\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Use this to find x. \n" ); document.write( "Pick either equation to plug in y = -11 \n" ); document.write( "I'll select the first equation \n" ); document.write( "5x-2y = 12 \n" ); document.write( "5x-2(-11) = 12 \n" ); document.write( "5x+22 = 12 \n" ); document.write( "5x = 12-22 \n" ); document.write( "5x = -10 \n" ); document.write( "x = -10/5 \n" ); document.write( "x = -2\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "We have x = -2 and y = -11 pairing up together to get us the ordered pair solution (x,y) = (-2,-11)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "We can confirm this through a graph \n" ); document.write( " ![]() \n" ); document.write( "Here's the link to the interactive page \n" ); document.write( "https://www.desmos.com/calculator/doa1oqrje8 \n" ); document.write( "Desmos is a free graphing app that I use often. \n" ); document.write( "GeoGebra is another free graphing app I use all the time as well.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Notes: \n" ); document.write( "5x-2y = 12 goes through the points (0,-6) and (2,-1) \n" ); document.write( "-5x+6y = -56 goes through the points (4,-6) and (10,-1)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "------------------------------------------------------\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "A non-visual way to check the answer:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Plug (x,y) = (-2,-11) into the first equation \n" ); document.write( "5x-2y = 12 \n" ); document.write( "5(-2)-2(-11) = 12 \n" ); document.write( "-10+22 = 12 \n" ); document.write( "12 = 12 \n" ); document.write( "We get a true statement.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Do the same for the second equation \n" ); document.write( "-5x+6y = -56 \n" ); document.write( "-5(-2)+6(-11) = -56 \n" ); document.write( "10-66 = -56 \n" ); document.write( "-56 = -56 \n" ); document.write( "The second equation is confirmed as well.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Both equations are true when we plug in x = -2 and y = -11. \n" ); document.write( "Therefore, the solution has been fully confirmed.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "We can use WolframAlpha to help confirm the answer \n" ); document.write( "In the search bar, type in 5x - 2y = 12 and -5x + 6y = -56 \n" ); document.write( "You could replace the \"and\" with a comma if you prefer. \n" ); document.write( "This is what you should get \n" ); document.write( " ![]() \n" ); document.write( "Here's the link \n" ); document.write( "https://www.wolframalpha.com/input?i=5x+-+2y+%3D+12+and+-5x+%2B+6y+%3D+-56 \n" ); document.write( "WolframAlpha offers a graph, though it may be in a format you are unfamiliar with. \n" ); document.write( " ![]() \n" ); document.write( "Notice the graphing window doesn't have the origin anywhere in view. This is because we're centered more around (-2,-11) which places us southwest of the origin. The good news is that the numbers along the side should help pinpoint where we are.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "There are other software tools to quickly check the answer. With GeoGebra, you would type in Solve[{5x - 2y = 12,-5x + 6y = -56}] \n" ); document.write( "The use of square brackets and curly braces are necessary. Feel free to explore your favorite software option to check the answer. \n" ); document.write( "Though please don't rely on the software to replace your brain and do your homework for you. You'll still need practice when the exams happen. \n" ); document.write( " \n" ); document.write( " |