document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=131941>Question 131941</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Find the variation constant and an equation of variation where y varies directly as x and y80 when x=10\r<BR>\n" );
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document.write( "THe variation constant is K=<BR>\n" );
document.write( "The equation of variation is y= </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #96421 by </B><A HREF=/tutors/aboutme.mpl?userid=bucky><B>bucky(2189)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=bucky><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=96421\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> If y varies directly as x, then the variation equation is of the form:<BR>\n" );
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document.write( "y = K*x<BR>\n" );
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document.write( "You are told that y = 80 when x = 10. Substitute these two values into the equation and<BR>\n" );
document.write( "you get:<BR>\n" );
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document.write( "80 = K*10<BR>\n" );
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document.write( "Solve for K by dividing both sides of the equation by 10 to get:<BR>\n" );
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document.write( "80/10 = K<BR>\n" );
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document.write( "The left side reduces to 8 so you have:<BR>\n" );
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document.write( "8 = K<BR>\n" );
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document.write( "Now you can return to the form of the \"direct variation\" equation and substitute 8 for k to<BR>\n" );
document.write( "get the equation:<BR>\n" );
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document.write( "y = 8*x<BR>\n" );
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document.write( "And there you are ... <BR>\n" );
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document.write( "the variation constant is K = 8 <BR>\n" );
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document.write( "and the equation of variation is y = 8*x<BR>\n" );
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document.write( "Hope this helps you to understand the problem. The key to these problems is knowing that<BR>\n" );
document.write( "the equation of direct variation is of the form:<BR>\n" );
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document.write( "y = K*x<BR>\n" );
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document.write( "And the equation of inverse variation is of the form:<BR>\n" );
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document.write( "y = K/x<BR>\n" );
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document.write( " </SPAN>\n" );
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