document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=211249>Question 211249</A>This question is from textbook <A HREF=http://www.amazon.com/exec/obidos/ASIN/9780618627196/algebrahomeworkh></A><BR>\n" );
document.write( ": <I><SPAN STYLE=\"word-break: break-all;\"> I'm trying to find the x-intercepts for the equation Y=16-4x^2.  What I've tried to do is change the y to 0, and factor the rest of the equation, but I keep getting left with a 4 that I can't seem to get rid of.  My Algebra skills are a little rusty...please help.  \r<BR>\n" );
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document.write( "0=4(4-x^2)<BR>\n" );
document.write( "0=4(2+x)(2-x)<BR>\n" );
document.write( "0=-2<BR>\n" );
document.write( "0=2<BR>\n" );
document.write( "(-2,0) and (2,0) are the x intercepts and the answers at the solutions part of the book, but why is that 4 still there?<BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #159609 by </B><A HREF=/tutors/aboutme.mpl?userid=Earlsdon><B>Earlsdon(6294)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Earlsdon><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=159609\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Remeber the \"zero product\" rule?<BR>\n" );
document.write( "If <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=a%2Ab+=+0 ALIGN=MIDDLE  ALT=\"a%2Ab+=+0\"   DISABLED_style= \"max-width:90%; height:auto;\" > the either <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=a+=+0 ALIGN=MIDDLE  ALT=\"a+=+0\"   DISABLED_style= \"max-width:90%; height:auto;\" > or <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=b+=+0 ALIGN=MIDDLE  ALT=\"b+=+0\"   DISABLED_style= \"max-width:90%; height:auto;\" > or both.<BR>\n" );
document.write( "Your work so far is immpecable. When you get to the line:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=0+=+4%282%2Bx%29%282-x%29 ALIGN=MIDDLE  ALT=\"0+=+4%282%2Bx%29%282-x%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > Apply the zero product rule:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=4+=+0 ALIGN=MIDDLE  ALT=\"4+=+0\"   DISABLED_style= \"max-width:90%; height:auto;\" > Clearly not true.<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=2%2Bx+=+0 ALIGN=MIDDLE  ALT=\"2%2Bx+=+0\"   DISABLED_style= \"max-width:90%; height:auto;\" > thus <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+x+=+-2 ALIGN=MIDDLE  ALT=\"+x+=+-2\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=2-x+=+0 ALIGN=MIDDLE  ALT=\"2-x+=+0\"   DISABLED_style= \"max-width:90%; height:auto;\" > thus <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x+=+2 ALIGN=MIDDLE  ALT=\"x+=+2\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "You can ignore the 4 as it is not pertinent to the x-intercepts.<BR>\n" );
document.write( "Another way to look at doing this problem (if the 4 still bothers you) is:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=-4x%5E2%2B16+=+0 ALIGN=MIDDLE  ALT=\"-4x%5E2%2B16+=+0\"   DISABLED_style= \"max-width:90%; height:auto;\" > Divide both sides by -4.<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x%5E2-4+=+0 ALIGN=MIDDLE  ALT=\"x%5E2-4+=+0\"   DISABLED_style= \"max-width:90%; height:auto;\" > Factor.<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28x-2%29%28x%2B2%29+=+0 ALIGN=MIDDLE  ALT=\"%28x-2%29%28x%2B2%29+=+0\"   DISABLED_style= \"max-width:90%; height:auto;\" > Apply the zero product rule.<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x-2+=+0 ALIGN=MIDDLE  ALT=\"x-2+=+0\"   DISABLED_style= \"max-width:90%; height:auto;\" > or <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x%2B2%29=+0 ALIGN=MIDDLE  ALT=\"x%2B2%29=+0\"   DISABLED_style= \"max-width:90%; height:auto;\" > so...<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x+=+2 ALIGN=MIDDLE  ALT=\"x+=+2\"   DISABLED_style= \"max-width:90%; height:auto;\" > or <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x+=+-2 ALIGN=MIDDLE  ALT=\"x+=+-2\"   DISABLED_style= \"max-width:90%; height:auto;\" > and these are the x-intercepts.<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=graph%28400%2C400%2C-5%2C5%2C-5%2C20%2C-4x%5E2%2B16%29 ALIGN=MIDDLE  ALT=\"graph%28400%2C400%2C-5%2C5%2C-5%2C20%2C-4x%5E2%2B16%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >  </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );