document.write( "Question 707913: can you please help me with this problem:\r
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document.write( "-12x-10y=90
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document.write( "-6x-y=9\r
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document.write( "what is the x and y values?
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document.write( "can you show all the steps please? :) \n" );
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Algebra.Com's Answer #435911 by jim_thompson5910(35256)![]() ![]() ![]() You can put this solution on YOUR website! Multiply both sides in equation 2 by the number -2 to get\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "-6x-y=9\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "-2(-6x-y)= -2*9\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "12x + 2y = -18\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "-------------------------------------------------------------------\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "So the system\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "-12x-10y=90 \n" ); document.write( "-6x-y=9 \r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "turns into\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "-12x-10y=90 \n" ); document.write( "12x+2y=-18\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Add the equations\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "-12x-10y=90 \n" ); document.write( "12x+2y=-18 \n" ); document.write( "----------- \n" ); document.write( "0x-8y=72\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "So -8y = 72. Solve for y\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "-8y = 72\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "y = 72/(-8)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "y = -9\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Now use this to find x.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "-12x-10y=90\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "-12x-10(-9)=90\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "-12x+90=90\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "-12x=90-90\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "-12x=0\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "x = 0/(-12)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "x = 0\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "So x = 0 and y = -9\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Therefore, the solution as an ordered pair is (0, -9)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "If you graphed both equations, you'll see that they intersect at (0, -9) which would give you visual confirmation of the answer. \n" ); document.write( " |