document.write( "Question 163395This question is from textbook Algebra and Trigonometry
\n" ); document.write( ": given: f(x)=5x-x^2
\n" ); document.write( "find: f(5-h)-f(5)/h
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Algebra.Com's Answer #120379 by gonzo(654)\"\" \"About 
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given: f(x)=5x-x^2
\n" ); document.write( "find: f(5-h)-f(5)/h
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\n" ); document.write( "f(x) = 5*x - x^2
\n" ); document.write( "f(5-h) is gotten by replacing x with (5-h), so
\n" ); document.write( "\"f%285-h%29+=+5%2A%285-h%29+-+%285-h%29%5E2\"
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\n" ); document.write( "f(5) is gotten by replacing x with 5, so
\n" ); document.write( "\"f%285%29+=+5%2A5+-+%285%29%5E2\"
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\n" ); document.write( "since there is no parentheses around it, your formula f(5-h)-f(5)/h
\n" ); document.write( "is assumed to be:
\n" ); document.write( "\"f%285-h%29+-+%28f%285%29%2Fh%29\"
\n" ); document.write( "-----
\n" ); document.write( "if you meant \"%28f%285-h%29+-+f%285%29%29%2Fh\", that would be a different equation.
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\n" ); document.write( "i'll solve for
\n" ); document.write( "\"f%285-h%29+-+%28f%285%29%2Fh%29\"
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\n" ); document.write( "
\n" ); document.write( "this becomes
\n" ); document.write( "\"25+-+5%2Ah+-+%2825-10%2Ah+%2B+h%5E2%29+-+%28%2825-25%29%2Fh%29\"
\n" ); document.write( "which becomes
\n" ); document.write( "\"25+-+5%2Ah+-+25+%2B+10%2Ah+-+h%5E2+-+%280%2Fh%29\"
\n" ); document.write( "which becomes
\n" ); document.write( "\"5%2Ah+-+h%5E2\"
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\n" ); document.write( "as far as i can tell.
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\n" ); document.write( "if you really meant \"%28f%285-h%29+-+f%285%29%29%2Fh\", then the equation becomes
\n" ); document.write( "\"%285%2A%285-h%29+-+%285-h%29%5E2+-+%285%2A5+-+%285%29%5E2%29%29%2Fh\"
\n" ); document.write( "which becomes
\n" ); document.write( "\"%2825+-+5%2Ah+-+25+%2B+10%2Ah+-+h%5E2+-+25+%2B+25%29%2Fh\"
\n" ); document.write( "which becomes
\n" ); document.write( "\"%285%2Ah+-+h%5E2%29+%2F+h\"
\n" ); document.write( "which becomes
\n" ); document.write( "\"5+-+h\"
\n" ); document.write( "-----
\n" ); document.write( "either way the key is to substitute (5-h) for x in f(5-h), and to substitute (5) for x in f(5)
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