document.write( "Question 116815: If f(x) = 2x + 3 and g(x) = (x - 3)/2, what is the value of f[g(-5)]?
\n" ); document.write( " If f(x) = 5x - 7, what is f -1(x)? \n" ); document.write( "

Algebra.Com's Answer #84950 by Fombitz(32388) $\"\"$ $\"About$

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If f(x) = 5x - 7, what is f -1(x)?
\n" ); document.write( " $\"g%28x%29=%28x-3%29%2F2\"$
\n" ); document.write( " $\"g%28-5%29=%28-5-3%29%2F2\"$
\n" ); document.write( " $\"g%28-5%29=-4\"$
\n" ); document.write( " $\"f%28x%29=2x%2B3\"$
\n" ); document.write( " $\"f%28g%28-5%29%29=f%28-4%29=2%28-4%29%2B3\"$
\n" ); document.write( " $\"f%28g%28-5%29%29=-5\"$
\n" ); document.write( "To find the inverse, we have to find a function g such that,
\n" ); document.write( " $\"f%28g%28x%29%29=x\"$
\n" ); document.write( " $\"f%28g%28x%29%29=5g-7=x\"$
\n" ); document.write( " $\"5g-7=x\"$
\n" ); document.write( " $\"5g=x%2B7\"$
\n" ); document.write( " $\"g=%28x%2B7%29%2F5\"$
\n" ); document.write( " $\"f%5E-1%28x%29=g%28x%29=%28x%2B7%29%2F5\"$ \n" ); document.write( "

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