document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=134911>Question 134911</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Can you please help me?<BR>\n" );
document.write( "find the variation equation for the variation statement.\r<BR>\n" );
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document.write( "z varies jointly as y and the cube of x; z=160 when x=2 and y=-5\r<BR>\n" );
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document.write( "Thanks again </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #98779 by </B><A HREF=/tutors/aboutme.mpl?userid=nycsharkman><B>nycsharkman(136)</B></A><img src=\"/images/stars/stars-09.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=nycsharkman><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=98779\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> This question is asking for the EQUATION and thus it is NOT asking you to solve for any letters in particular.\r<BR>\n" );
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document.write( "If z varies jointly as y and the cube of x, then we have this equation:\r<BR>\n" );
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document.write( "z = k(x^3)(y), where k is the constant of variation.\r<BR>\n" );
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document.write( "Let plug the given numbers WITHOUT solving for k.\r<BR>\n" );
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document.write( "160 = k(2)^3(-5)\r<BR>\n" );
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document.write( "160 = k(8)(-5)\r<BR>\n" );
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document.write( "160 = -40k\r<BR>\n" );
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document.write( "You said:\r<BR>\n" );
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document.write( "\"I was looking for: y=-4xy^3, y=4x^3y, y=4xy^3, y=-4x^3y\"\r<BR>\n" );
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document.write( "I said:<BR>\n" );
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document.write( "In the question, you did not indicate that the constant of variation, which is k needed to be found.<BR>\n" );
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document.write( "I found this equation:<BR>\n" );
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document.write( "160 = -40k<BR>\n" );
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document.write( "Divide both sides by -40 and k = -4.<BR>\n" );
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document.write( "Then your equation and answer is:<BR>\n" );
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document.write( "z = -4x^3y <BR>\n" );
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document.write( "It cannot be y = -4x^3y because z varies jointly as y and the cube of x.<BR>\n" );
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document.write( "In other words, if your question has a letter z, then z MUST appear or be part of your equation.<BR>\n" );
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