document.write( "Question 1199369: Solve the inequality. \r
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document.write( "|-4x| + |-5| ≤ 1\r
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document.write( "|-4x| + -5 ≤ 1\r
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document.write( "|-4x| + ≤ 1 + 5\r
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document.write( "|-4x| ≤ 6\r
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document.write( "-6 < -4x < 6\r
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document.write( "-6/-4 > x > 6/-4\r
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document.write( "3/2 > x > -3/2\r
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document.write( "Let S = solution set\r
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document.write( "My answer: S = {x | 3/2 > x > -3/2}\r
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document.write( "Textbook answer: No solution.\r
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document.write( "What did I do wrong? Why is the empty set or no solution the right answer? \r
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document.write( "
Algebra.Com's Answer #833227 by ikleyn(52776)![]() ![]() You can put this solution on YOUR website! .\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " You are wrong starting from the FIRST LINE of your solution.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " The correct solution is as follows.\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \r\n" ); document.write( "Our starting inequality is\r\n" ); document.write( "\r\n" ); document.write( " |-4x| + |-5| ≤ 1.\r\n" ); document.write( "\r\n" ); document.write( "\r\n" ); document.write( "Notice that |-4x| = |4x| and |-5| = 5. \r\n" ); document.write( "\r\n" ); document.write( "Therefore, we can rewrite the starting inequality in this equivalent form\r\n" ); document.write( "\r\n" ); document.write( " |4x| + 5 <= 1\r\n" ); document.write( "\r\n" ); document.write( "and then, subtracting 5 from both sides\r\n" ); document.write( "\r\n" ); document.write( " |4x| <= 1 - 5\r\n" ); document.write( "\r\n" ); document.write( " |4x| < -4.\r\n" ); document.write( "\r\n" ); document.write( "\r\n" ); document.write( "But the number (absolute value) |4x| is always non-negative, so it can not be lesser than negative 4.\r\n" ); document.write( "\r\n" ); document.write( "\r\n" ); document.write( "Hence, the original equation has no solution.\r\n" ); document.write( "\r\n" ); document.write( "\r\n" ); document.write( "Exactly as it is stated in your textbook.\r\n" ); document.write( "\r \n" ); document.write( "\n" ); document.write( "Solved and fully explained.\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |