document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=661103>Question 661103</A>: <I><SPAN STYLE=\"word-break: break-all;\"> If a rock falls from a height of 20 meter on the planet Jupiter, its height H (in meters) after x seconds is approximately H(x)=20-13x^2\r<BR>\n" );
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document.write( "When is the height of the rock 15 meters?\r<BR>\n" );
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document.write( "I have already plugged 15 meters into the equation like this 15=20-13x^2<BR>\n" );
document.write( "How do I solve for x? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #411509 by </B><A HREF=/tutors/aboutme.mpl?userid=lynnlo><B>lynnlo(4176)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=lynnlo><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=411509\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> 15=20-13x^2<BR>\n" );
document.write( "(1)reverse the equality in 15=20-13x^2<BR>\n" );
document.write( "it is the same as 20-13x^2=15<BR>\n" );
document.write( "(2)isolate terms with x to the left side<BR>\n" );
document.write( "subtract 20 from both sides<BR>\n" );
document.write( "-13x^2=-5<BR>\n" );
document.write( "(3)divide both sides by a constant to simplify<BR>\n" );
document.write( "divide both sides by -13=x^2=5/3<BR>\n" );
document.write( "(4)eliminate exponent on left side,take the square root both sides<BR>\n" );
document.write( "answer====x=&#8730;5/13  OR x=-&#8730;5/13 </SPAN>\n" );
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