document.write( "Question 209593: Solve each equation. Check for extraneous solutions.\r
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document.write( "Equation: |5x-1|+7=3x\r
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document.write( "Here's what I did:\r
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document.write( "|5x-1|+7=3x
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document.write( " -7 -7\r
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document.write( "|5x+1|=3x-7\r
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document.write( "5x-1=3x-7 OR 5x-1=-(3x-7)
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document.write( " +1 +1
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document.write( "5x=3x-6
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document.write( "-3x -3x
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document.write( "2x=-6
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document.write( "-- --
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document.write( "2 2
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document.write( "x=-3\r
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document.write( "OR
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document.write( "5x-1=-(3x-7)
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document.write( "5x-1=-3x\r
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document.write( "So, x=-3 or x=1.\r
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document.write( "CHECK:
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document.write( "|5x-1|+7=3x
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document.write( "|5(-3)-1|+7=+3(-3)
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document.write( "|-15-1|+7=-9
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document.write( "|-16|+7=-9
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document.write( "16+7=-9
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document.write( "23=9
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document.write( "But 23 doesn't equal 9. At first I thought it was just an exraneous solution. But then I checked the second number:\r
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document.write( "|5x-1|+7=3x
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document.write( "|5(1)-1|+7=3(1)
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document.write( "|5-1|+7=3
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document.write( "|4|+7=3
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document.write( "4+7=3
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document.write( "11=3
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document.write( "But again, 11 doesn't equal 3. \n" );
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Algebra.Com's Answer #158488 by stanbon(75887)![]() ![]() ![]() You can put this solution on YOUR website! Solve each equation. Check for extraneous solutions. \n" ); document.write( "Equation: |5x-1|+7=3x \n" ); document.write( "Here's what I did: \n" ); document.write( "|5x-1|+7=3x \n" ); document.write( "-7 -7 \n" ); document.write( "|5x+1|=3x-7 \n" ); document.write( "5x-1=3x-7 OR 5x-1=-(3x-7) \n" ); document.write( "+1 +1 \r \n" ); document.write( "\n" ); document.write( "5x=3x-6 \n" ); document.write( "-3x -3x \r \n" ); document.write( "\n" ); document.write( "2x=-6 \n" ); document.write( "-- -- \n" ); document.write( "2 2 \r \n" ); document.write( "\n" ); document.write( "x=-3 \n" ); document.write( "OR \n" ); document.write( "5x-1=-(3x-7) \n" ); document.write( "5x-1=-3x+7 \n" ); document.write( "8x = 8 \n" ); document.write( "x = 1 \n" ); document.write( "So, x=-3 or x=1. \n" ); document.write( "CHECK: \n" ); document.write( "|5x-1|+7=3x \n" ); document.write( "|5(-3)-1|+7=+3(-3) \n" ); document.write( "|-15-1|+7=-9 \n" ); document.write( "|-16|+7=-9 \n" ); document.write( "16+7=-9 \n" ); document.write( "23=9 \n" ); document.write( "But 23 doesn't equal 9. At first I thought it was just an exraneous solution. But then I checked the second number: \n" ); document.write( "|5x-1|+7=3x \n" ); document.write( "|5(1)-1|+7=3(1) \n" ); document.write( "|5-1|+7=3 \n" ); document.write( "|4|+7=3 \n" ); document.write( "4+7=3 \n" ); document.write( "11=3 \n" ); document.write( "But again, 11 doesn't equal 3. \n" ); document.write( "----------------------------------------- \n" ); document.write( "Your work is correct. \n" ); document.write( "Both \"solution\" are extraneous. \n" ); document.write( "--- \n" ); document.write( "If you graph the left side and the right side of the equation \n" ); document.write( "separately, you will see that they do not intersect, i.e. they \n" ); document.write( "are never equal. \n" ); document.write( "======================= \n" ); document.write( "Cheers, \n" ); document.write( "Stan H. \n" ); document.write( "Reply to stanbon@comcast.net \n" ); document.write( " |