document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=381187>Question 381187</A>: <I><SPAN STYLE=\"word-break: break-all;\"> the function f(x)=(5x/x+7) is one to one find the inverse of f and the range of f using the inverse. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #270407 by </B><A HREF=/tutors/aboutme.mpl?userid=Jk22><B>Jk22(389)</B></A><img src=\"/images/stars/stars-10.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Jk22><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/cgi-bin/show-face.mpl?user=Jk22><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=270407\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> from f(x)=5x/(x+7), we shall have x<>-7<BR>\n" );
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document.write( "let write f(x)=y, then y*(x+7)=5x=yx+7y<BR>\n" );
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document.write( "x(5-y)=7y => y = 7y/(5-y), hence y should be different from 5<BR>\n" );
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document.write( "Check : x(f(x))=7*5x/(x+7)/(5-5x/(x+7))=35x/(x+7)*(x+7)/(5x+35-5x)<BR>\n" );
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document.write( "=35x/35=x </SPAN>\n" );
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