document.write( "Question 295955: Hi, what is the log of log7 50=
\n" ); document.write( "Sorry, I am not sure how to make the 7 a subscript.\r
\n" ); document.write( "\n" ); document.write( "I understand I am trying to find the exponent of 7 that will produce 50.
\n" ); document.write( "7 squared is 49, so what do I do from there?\r
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\n" ); document.write( "\n" ); document.write( "Thanking You in Advance,
\n" ); document.write( "Jacinta\r
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Algebra.Com's Answer #213320 by Theo(13342)\"\" \"About 
You can put this solution on YOUR website!
Your equation is:\r
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\n" ); document.write( "\n" ); document.write( "\"log%287%2C50%29+=+y\"\r
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\n" ); document.write( "\n" ); document.write( "This is true, if and only if \"7%5Ey+=+50\"\r
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\n" ); document.write( "\n" ); document.write( "Take the log of both sides of this equation to get:\r
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\n" ); document.write( "\n" ); document.write( "this log you are taking is to the base 10 which is the LOG function of your calculator.\r
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\n" ); document.write( "\n" ); document.write( "\"log%2810%2C7%5Ey%29+=+log%2810%2C50%29\"\r
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\n" ); document.write( "\n" ); document.write( "Since, in general, \"log%28x%5Ey%29+=+y%2Alog%28x%29\", this equation becomes:\r
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\n" ); document.write( "\n" ); document.write( "\"y%2Alog%2810%2C7%29+=+log%2810%2C50%29\"\r
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\n" ); document.write( "\n" ); document.write( "Divide both sides of this equation by \"log%2810%2C7%29\" to get:\r
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\n" ); document.write( "\n" ); document.write( "\"y+=+log%2810%2C50%29%2Flog%2810%2C7%29\" ***** \r
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\n" ); document.write( "\n" ); document.write( "***** This equation is the log base conversion formula described below.\r
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\n" ); document.write( "\n" ); document.write( "Use your calculator to get log of 50 divided by log of 10 to get:\r
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\n" ); document.write( "\n" ); document.write( "\"y+=+1.698970004%2F.84509804\" which becomes:\r
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\n" ); document.write( "\n" ); document.write( "\"y+=+2.010382138\"\r
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\n" ); document.write( "\n" ); document.write( "That's your answer:\r
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\n" ); document.write( "\n" ); document.write( "Plug into your original equation to get:\r
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\n" ); document.write( "\n" ); document.write( "\"log%287%2C50%29+=+y\" becomes:\r
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\n" ); document.write( "\n" ); document.write( "\"log%287%2C50%29+=+2.010382138\"\r
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\n" ); document.write( "\n" ); document.write( "this is true if and only if:\r
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\n" ); document.write( "\n" ); document.write( "\"7%5E2.010382138+=+50\"\r
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\n" ); document.write( "\n" ); document.write( "Use your calculator to determine that \"7%5E2.010382138\" = 50, confirming that the answer of y = 2.010382138 is good.\r
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\n" ); document.write( "\n" ); document.write( "You needed to know that, in general:\r
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\n" ); document.write( "\n" ); document.write( "\"log%28b%2Cx%29+=+y\" if and only if \"b%5Ey+=+x\"\r
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\n" ); document.write( "\n" ); document.write( "There is also a log base conversion formula that will provide you with the same answer.\r
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\n" ); document.write( "\n" ); document.write( "That conversion formula is:\r
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\n" ); document.write( "\n" ); document.write( "y = \"log%28b%2Cx%29+=+log%28c%2Cx%29+%2F+log%28c%2Cb%29\"\r
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\n" ); document.write( "\n" ); document.write( "In your case, this conversion formula would work like this:\r
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\n" ); document.write( "\n" ); document.write( "y = \"log%287%2C50%29+=+log%2810%2C50%29+%2F+log%2810%2C7%29\"\r
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\n" ); document.write( "\n" ); document.write( "If you look at what we did earlier, you will see that our solution yielded this exact formula.\r
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\n" ); document.write( "\n" ); document.write( "That would be the equation denoted with ***** up above.\r
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\n" ); document.write( "\n" ); document.write( "That equation was \"y+=+log%2810%2C50%29%2Flog%2810%2C7%29\"\r
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\n" ); document.write( "\n" ); document.write( "Our conversion equation here is:\r
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\n" ); document.write( "\n" ); document.write( "y = \"log%287%2C50%29+=+log%2810%2C50%29+%2F+log%2810%2C7%29\"\r
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\n" ); document.write( "\n" ); document.write( "y = \"log%287%2C50%29\" is your original equation.\r
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\n" ); document.write( "\n" ); document.write( "y = \"log%2810%2C50%29+%2F+log%2810%2C7%29\" is the conversion equation.\r
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