document.write( "Question 1209283: If 1/a + 1/b = 5/12 and ab = 24, what is the value of a+b? \n" ); document.write( "
Algebra.Com's Answer #848099 by math_tutor2020(3817)\"\" \"About 
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\n" ); document.write( "There are at least three ways to answer this question. \r
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\n" ); document.write( "\n" ); document.write( "Method 1\r
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\n" ); document.write( "\n" ); document.write( "\"1%2Fa+%2B+1%2Fb+=+5%2F12\"\r
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\n" ); document.write( "\n" ); document.write( "\"b%2F%28ab%29+%2B+a%2F%28ab%29+=+10%2F24\"\r
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\n" ); document.write( "\n" ); document.write( "\"%28b+%2B+a%29%2F%28ab%29+=+10%2F24\"\r
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\n" ); document.write( "\n" ); document.write( "\"%28a%2Bb%29%2F%2824%29+=+10%2F24\" Plug in ab = 24.\r
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\n" ); document.write( "\n" ); document.write( "\"a%2Bb+=+10\" \r
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\n" ); document.write( "\n" ); document.write( "Method 2\r
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\n" ); document.write( "\n" ); document.write( "\"1%2Fa+%2B+1%2Fb+=+5%2F12\"\r
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\n" ); document.write( "\n" ); document.write( "\"ab%2A%281%2Fa+%2B+1%2Fb%29+=+ab%2A%285%2F12%29\" Multiply both sides by ab\r
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\n" ); document.write( "\n" ); document.write( "\"ab%2A%281%2Fa%29+%2B+ab%2A%281%2Fb%29+=+ab%2A%285%2F12%29\" Distribute\r
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\n" ); document.write( "\n" ); document.write( "\"b+%2B+a+=+ab%2A%285%2F12%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"a%2Bb+=+24%2A%285%2F12%29\" Plug in ab = 24\r
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\n" ); document.write( "\n" ); document.write( "\"a%2Bb+=+10\" \r
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\n" ); document.write( "\n" ); document.write( "Method 3\r
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\n" ); document.write( "\n" ); document.write( "ab = 24 rearranges to b = 24/a which has reciprocal 1/b = a/24\r
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\n" ); document.write( "\n" ); document.write( "Then,
\n" ); document.write( "\"1%2Fa+%2B+1%2Fb+=+5%2F12\"\r
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\n" ); document.write( "\n" ); document.write( "\"1%2Fa+%2B+a%2F24+=+5%2F12\" Replaced 1/b with a/24\r
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\n" ); document.write( "\n" ); document.write( "\"%281%2Fa+%2B+a%2F24%29%2A24a+=+%285%2F12%29%2A24a\" Multiply both sides by the LCD 24a to clear out the fractions.\r
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\n" ); document.write( "\n" ); document.write( "\"%281%2Fa%29%2A24a+%2B+%28a%2F24%29%2A24a+=+10a\"\r
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\n" ); document.write( "\n" ); document.write( "\"24+%2B+a%5E2+=+10a\"\r
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\n" ); document.write( "\n" ); document.write( "\"a%5E2-10a%2B24+=+0\"\r
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\n" ); document.write( "\n" ); document.write( "\"%28a-6%29%28a-4%29+=+0\"\r
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\n" ); document.write( "\n" ); document.write( "\"a-6=0\" or \"a-4=0\"\r
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\n" ); document.write( "\n" ); document.write( "\"a+=+6\" or \"a+=+4\"\r
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\n" ); document.write( "\n" ); document.write( "If a = 6, then b = 24/a = 24/6 = 4.
\n" ); document.write( "If a = 4, then b = 24/a = 24/4 = 6.
\n" ); document.write( "The order of a,b doesn't matter so we arrive at the same pairing.\r
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\n" ); document.write( "\n" ); document.write( "The pair of values is a = 4 and b = 6 (or a = 6 and b = 4).
\n" ); document.write( "As a way to check, \"1%2Fa+%2B+1%2Fb+=+1%2F4+%2B+1%2F6+=+3%2F12+%2B+2%2F12+=+%283%2B2%29%2F12+=+5%2F12\"\r
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\n" ); document.write( "\n" ); document.write( "In short \"1%2F4+%2B+1%2F6+=+5%2F12\" which helps us confirm we have the correct a,b values.\r
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\n" ); document.write( "\n" ); document.write( "Then a+b = 4+6 = 10\r
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\n" ); document.write( "\n" ); document.write( "Answer: 10
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