document.write( "Question 230847: f(x)=-9x/4 +7 Need the algebraically inverse function \n" ); document.write( "

Algebra.Com's Answer #170979 by likaaka(51) $\"\"$ $\"About$

You can put this solution on YOUR website!
To find the inverse, begin by changing f(x) to y
\n" ); document.write( "f(x)=(-9x/4) + 7
\n" ); document.write( "y = (-9x/4) + 7
\n" ); document.write( "Now, solve for x
\n" ); document.write( "y = (-9x/4) + 7
\n" ); document.write( "y - 7 = (-9x/4) + 7 - 7, subtract 7 from both sides
\n" ); document.write( "y - 7 = -9x/4
\n" ); document.write( "4(y - 7) = 4(-9x/4), multiply both sides by 4
\n" ); document.write( "4y - 28 = -9x
\n" ); document.write( "(4y - 28)/(-9) = (-9x)/(-9), divide both sides by -9
\n" ); document.write( "(4y - 28)/(-9) = x
\n" ); document.write( "Now change x to y and y to x
\n" ); document.write( "(4x - 28)/(-9) = y, this is the inverse function
\n" ); document.write( "Inverse functions are usually written as f^-1(x)
\n" ); document.write( " $\"+f%5E-1%28x%29+=+%284x+-+28%29%2F%28-9%29+\"$ \n" ); document.write( "

\n" );