document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=858165>Question 858165</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The variable z varies directly with x and inversely with the cube of y. <BR>\n" );
document.write( "a) Write the formula for this variation. <BR>\n" );
document.write( "b) If z=12/27 when x=6 and y=3 find z when x=5 and y=4. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #517068 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><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/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=517068\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> The variable z varies directly with x and inversely with the cube of y. <BR>\n" );
document.write( "a) Write the formula for this variation.<BR>\n" );
document.write( "z = k*x/y^3<BR>\n" );
document.write( "----------------------- <BR>\n" );
document.write( "b) If z=12/27 when x=6 and y=3 <BR>\n" );
document.write( "Find \"k\"::<BR>\n" );
document.write( "12/27 = k*6/3^3<BR>\n" );
document.write( "-----<BR>\n" );
document.write( "12 = 6k<BR>\n" );
document.write( "k = 2<BR>\n" );
document.write( "-----<BR>\n" );
document.write( "Equation:<BR>\n" );
document.write( "y = 2x/y^3<BR>\n" );
document.write( "-------------------<BR>\n" );
document.write( "find z when x=5 and y=4.<BR>\n" );
document.write( "z = 2*5/4^3<BR>\n" );
document.write( "z = 10/64<BR>\n" );
document.write( "---------------------<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
document.write( "---------------------<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );