document.write( "Question 837943: Let f(x) = px + q, where p and q are real numbers. Find p+q if f(f(f(x))) = 8x + 21. \n" ); document.write( "

Algebra.Com's Answer #505280 by Fombitz(32388) $\"\"$ $\"About$

You can put this solution on YOUR website!
$\"f%28x%29=px%2Bq\"$
\n" ); document.write( " $\"f%28f%28x%29%29=p%28px%2Bq%29%2Bq=p%5E2x%2Bqp%2Bq\"$
\n" ); document.write( " $\"f%28f%28f%28x%29%29%29=p%5E2%28px%2Bq%29%2Bqp%2Bq\"$
\n" ); document.write( " $\"f%28f%28f%28x%29%29%29=p%5E3x%2Bp%5E2q%2Bpq%2Bq=8x%2B21\"$
\n" ); document.write( " $\"p%5E3=8\"$
\n" ); document.write( " $\"p=2\"$
\n" ); document.write( " $\"p%5E2q%2Bpq%2Bq=21\"$
\n" ); document.write( " $\"4q%2B2q%2Bq=21\"$
\n" ); document.write( " $\"7q=21\"$
\n" ); document.write( " $\"q=7\"$
\n" ); document.write( " $\"highlight%28p%2Bq=2%2B7=9%29\"$
\n" ); document.write( " \n" ); document.write( "

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