document.write( "Question 110604: using the two equations below, solve for x and y using three different methods, substituion, addition and graphing.\r
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document.write( "-2x+3y=6
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document.write( "3x-5y=-11 \n" );
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Algebra.Com's Answer #80825 by ankor@dixie-net.com(22740)![]() ![]() You can put this solution on YOUR website! using the two equations below, solve for x and y using three different methods, substitution, addition and graphing. \n" ); document.write( "-2x + 3y = 6 \n" ); document.write( " 3x - 5y =-11 \n" ); document.write( ": \n" ); document.write( "Substitution: \n" ); document.write( "Rearrange the 1st equation to be used for subsitution: \n" ); document.write( "3y = 2x + 6 \n" ); document.write( "y = \n" ); document.write( "y = \n" ); document.write( ": \n" ); document.write( "Substitute ( \n" ); document.write( "3x - 5( \n" ); document.write( ": \n" ); document.write( "3x - \n" ); document.write( "; \n" ); document.write( " \n" ); document.write( ": \n" ); document.write( "- \n" ); document.write( ": \n" ); document.write( " \n" ); document.write( ": \n" ); document.write( "x = 3; Multiplied by 3 to get rid of the fraction \n" ); document.write( ": \n" ); document.write( "Find y using the y = \n" ); document.write( "y = \n" ); document.write( "y = 2 + 2 \n" ); document.write( "y = 4 \n" ); document.write( ": \n" ); document.write( "Our solution x = 3; y = 4 \n" ); document.write( ": \n" ); document.write( "Substitute for x and y in the 2nd equation to confirm our solutions: \n" ); document.write( "3x - 5y =-11 \n" ); document.write( ": \n" ); document.write( "3(3) - 5(4) = \n" ); document.write( "9 - 20 = -11 \n" ); document.write( ": \n" ); document.write( ": \n" ); document.write( "Elimination: \n" ); document.write( "-2x + 3y = 6 \n" ); document.write( " 3x - 5y =-11 \n" ); document.write( ": \n" ); document.write( "Multiply the 1st equation by 3 and the 2nd equation by 2: \n" ); document.write( "-6x + 9y = 18 \n" ); document.write( "+6x -10y = -22 \n" ); document.write( "---------------adding eliminates x, find y: \n" ); document.write( "0x - 1y = -4 \n" ); document.write( "y = +4 \n" ); document.write( "Find x just like we did before using substitution for y in either equation \n" ); document.write( ": \n" ); document.write( "To graph this: \n" ); document.write( "y = \n" ); document.write( "and \n" ); document.write( " 3x - 5y =-11 \n" ); document.write( "-5y = - 3x - 11 \n" ); document.write( "5y = 3x + 11; multiplied by -1 to get rid of all those negatives \n" ); document.write( "y = \n" ); document.write( ": \n" ); document.write( "Plot these to equations, should look like this \n" ); document.write( " \n" ); document.write( ": \n" ); document.write( "Not very clear but they should intersect at x=3, y=4 \n" ); document.write( ": \n" ); document.write( "How about this? Did it explain these three methods to you? \n" ); document.write( " \n" ); document.write( " |