document.write( "Question 250227: In a 3-by-3 linear system, there should be a tripled pair for the system.\r
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document.write( "This system being:\r
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document.write( "3x+3y+6z=9
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document.write( "2x+y+3z=7
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document.write( "x+2y-z=-10\r
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document.write( "what would be the work in solving this? I figured out the tripled pair, but my work doesn't seem to match up exactly. Would you please help me with this problem? At least start me off, so I can finish it! \n" );
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Algebra.Com's Answer #182158 by stanbon(75887)![]() ![]() ![]() You can put this solution on YOUR website! In a 3-by-3 linear system, there should be a tripled pair for the system. \n" ); document.write( "This system being: \n" ); document.write( "3x+3y+6z=9 \n" ); document.write( "2x+y+3z=7 \n" ); document.write( "x+2y-z=-10 \n" ); document.write( "-------------------- \n" ); document.write( "Let the 3rd equation be 1st: \n" ); document.write( "x+2y-z=-10 \n" ); document.write( "3x+3y+6z=9 \n" ); document.write( "2x+y+3z=7 \n" ); document.write( "---- \n" ); document.write( "Multiply 1st by 3 and subtract from the 2nd: \n" ); document.write( "Multiply 1st be 2 and subtract from the 3rd: \n" ); document.write( "x+2y-z=-10 \n" ); document.write( "0-3y+9z=39 \n" ); document.write( "0-3y+5z=27 \n" ); document.write( "----------------------- \n" ); document.write( "Subtract the 2nd from the 3rd: \n" ); document.write( "x+2y-z=-10 \n" ); document.write( "0-3y+9z=39 \n" ); document.write( "0-0y-4z=-12 \n" ); document.write( "----------------- \n" ); document.write( "Solve the 3rd equation for \"z\": \n" ); document.write( "z = 3 \n" ); document.write( "------------------- \n" ); document.write( "Substitute z=3 into the 2nd and solve for \"y\": \n" ); document.write( "-3y + 27 = 39 \n" ); document.write( "-3y = 12 \n" ); document.write( "y = -4 \n" ); document.write( "---------------------- \n" ); document.write( "Substitute z=3 and y = -4 into the 1st and solve for \"x\": \n" ); document.write( "x + 2(-4)-(3) = -10 \n" ); document.write( "x -8 - 3 = -10 \n" ); document.write( "x -11 = -10 \n" ); document.write( "x = 1 \n" ); document.write( "------------------------------ \n" ); document.write( "Final answer: x = 1 ; y = -4 ; z = 3 \n" ); document.write( "======================================== \n" ); document.write( "I checked this with a matrix method. \n" ); document.write( "It is correct. \n" ); document.write( "======================================== \n" ); document.write( "Cheers, \n" ); document.write( "Stan H.\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |