document.write( "Question 71396: Combine: (3/x(to the 2nd) + 3x - 4) - (4/x(to the 2nd) - 6x - 40)\r
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Algebra.Com's Answer #51072 by bucky(2189)\"\" \"About 
You can put this solution on YOUR website!
Combine \"%283%2Fx%5E2+%2B+3x+-+4%29+-+%284%2Fx%5E2+-+6x+-+40%29\"
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\n" ); document.write( "One of the first thing you can do is remove the parentheses by using the rules:
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\n" ); document.write( "(1) If a set of parentheses is preceded by a plus sign (no sign at all is assumed to be plus),
\n" ); document.write( "then just remove the parentheses without making changes to the terms within the parentheses.
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\n" ); document.write( "(2) If a set of parentheses is preceded by a minus sign you can remove the parentheses,
\n" ); document.write( "but you must change the signs of the terms within the parentheses. (A term that was plus
\n" ); document.write( "when it was within the parentheses becomes minus when the parentheses are removed. And a term
\n" ); document.write( "that was minus when it was within the parentheses becomes plus when the parentheses
\n" ); document.write( "are removed.)
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\n" ); document.write( "Note that the first set of parentheses (reading from left to right) does not have a
\n" ); document.write( "sign preceding it. Therefore, it is presumed to have a preceding plus sign and you can
\n" ); document.write( "remove the parentheses with out changing terms. This makes the problem:
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\n" ); document.write( "\"3%2Fx%5E2+%2B+3x+-+4+-+%284%2Fx%5E2+-+6x+-+40%29\"
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\n" ); document.write( "The remaining set of parentheses is preceded by a minus sign. Therefore, when you remove
\n" ); document.write( "the parentheses you must also change the sign of the three terms inside. When you do
\n" ); document.write( "this the problem becomes:
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\n" ); document.write( "\"3%2Fx%5E2+%2B+3x+-+4+-+4%2Fx%5E2+%2B+6x+%2B+40%29\"
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\n" ); document.write( "Notice that the +3x and the +6x can be added to give +9x. Notice also that the -4 and
\n" ); document.write( "the +40 can be added to get + 36. Make these two substitutions to make the problem
\n" ); document.write( "become:
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\n" ); document.write( "\"3%2Fx%5E2+-+4%2Fx%5E2+%2B+9x+%2B+36%29\"
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\n" ); document.write( "Now notice that you have two fractions left to deal with. They both have the same
\n" ); document.write( "denominator so their numerators can be added and the resulting term put over the common
\n" ); document.write( "denominator. Their numerators are +3 and -4. When you add them the answer is -1 and
\n" ); document.write( "this is put over the common denominator to get \"-1%2Fx%5E2\". When you substitute
\n" ); document.write( "this into the equation, the result is:
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\n" ); document.write( "\"-1%2Fx%5E2+%2B+9x+%2B+36%29\"
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\n" ); document.write( "As far as I'm concerned, that answer is correct. However, maybe your teacher wants
\n" ); document.write( "everything over the common denominator of \"x%5E2\". If so, multiply the \"9x\"
\n" ); document.write( "by \"x%5E2%2Fx%5E2\" and you get \"9x%5E3%2Fx%5E2\" and then multiply the \"36\" by \"x%5E2%2Fx%5E2\"
\n" ); document.write( "and you get \"36%2Ax%5E2%2Fx%5E2\". Now all the terms have the common denominator of \"x%5E2\"
\n" ); document.write( "so you can add their numerators and get \"%28-1+%2B+9x%5E3+%2B+36x%5E2%29%2Fx%5E2\" and as a
\n" ); document.write( "final
\n" ); document.write( "touch you can arrange the numerator in descending powers of x so that the answer is:
\n" ); document.write( "\"%289x%5E3+%2B+36x%5E2+-1%29%2Fx%5E2\"
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\n" ); document.write( "Check all the math above. It's pretty early in the morning and I haven't had a chance to
\n" ); document.write( "become fully awake. Feel free to correct any careless mistakes you find. I hope this
\n" ); document.write( "problem helps you to become familiar with some of the ways you can simplify algebraic
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