document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=167110>Question 167110</A>: <I><SPAN STYLE=\"word-break: break-all;\"> If y varies directly as the square of x, and y=7 when x=9, find y when x=7. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #123115 by </B><A HREF=/tutors/aboutme.mpl?userid=midwood_trail><B>midwood_trail(310)</B></A><img src=\"/images/stars/stars-10.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=midwood_trail><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=123115\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> If y varies directly as the square of x, and y=7 when x=9, find y when x=7.\r<BR>\n" );
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document.write( "y varies directly as x^2 is written y = kx^2, where k is the constant of variation.\r<BR>\n" );
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document.write( "y = 7 when x = 9.  Given this data, we first solve for k.\r<BR>\n" );
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document.write( "y = kx^2\r<BR>\n" );
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document.write( "7 = k(9)^2\r<BR>\n" );
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document.write( "7 = 81k\r<BR>\n" );
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document.write( "7/81 = k\r<BR>\n" );
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document.write( "We now multiply the value just found for k by 7^2 or 49 to find y.\r<BR>\n" );
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document.write( "y = (7/81)(7)^2\r<BR>\n" );
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document.write( "y = (7/81)(49)\r<BR>\n" );
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document.write( "y = 343/81\r<BR>\n" );
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document.write( "Did you follow?\r<BR>\n" );
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document.write( " </SPAN>\n" );
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