document.write( "Question 428586: Solve by graphing and then get an exact solution by using either substitution or elimination. (if you cant graph please just answer the second part)\r
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document.write( " y=2/3x+3
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document.write( " 3x-3y=-6 \n" );
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Algebra.Com's Answer #297867 by Theo(13342)![]() ![]() You can put this solution on YOUR website! your equations are:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "y = (2/3)*x + 3\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "and:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "3x - 3y = -6\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "in order to graph these equations, you need to solve for y.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the first one is already solved for y.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the second one is solved for y in the following manner:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "3x - 3y = -6 \n" ); document.write( "subtract 3x from both sides of the equation to get: \n" ); document.write( "-3y = -3x - 6 \n" ); document.write( "divide both sides of the equation by -3 to get: \n" ); document.write( "y = (-3/-3)*x - (6/-3) \n" ); document.write( "simplify this to get: \n" ); document.write( "y = x - (-2) \n" ); document.write( "simplify further to get: \n" ); document.write( "y = x + 2\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the 2 equations that you can now graph are:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "y = (2/3)x + 3 \n" ); document.write( "y = x + 2\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the graph of these equations is shown below:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the graph shows an intersection at somewhere around x = 3 and y = 5.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "you can solve these equations by substitution to see if the answer comes out somewhere near there.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "use the original equations of:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "y = (2/3)x + 3 \n" ); document.write( "3x - 3y = -6\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "since your first equation has already solved for y, you can use that to substitute for y in the second equation to get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "3x - 3y = -6 becomes 3x - 3*((2/3)x + 3) = -6\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "simplify by removing parentheses to get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "3x - 3*(2/3)x - 3*3 = -6\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "simpify further to get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "3x - 2x - 9 = -6\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "combine like terms to get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "x - 9 = -6\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "add 9 to both sides of the equation to gert:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "x = -6 + 9\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "simplify further to get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "x = 3\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "you now have x = 3 and you can substitute for x in either equation to solve for y.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "we'll use the first equation.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the first equation is y = (2/3)x + 3\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "substitute 3 for x to get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "y = (2/3)*3 + 3\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "simplify to get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "y = 2 + 3 which becomes y = 5\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "your solution for this set of simultaneous equations is:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "x = 3 \n" ); document.write( "y = 5\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "this is confirmed by the graph.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |