document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1068091>Question 1068091</A>: <I><SPAN STYLE=\"word-break: break-all;\"> PLEASE HELP ME!!\r<BR>\n" );
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document.write( "how do you write the equation of a parabola in the standard form y=ax^2+bx+c, given 2 points and the x-intercept??\r<BR>\n" );
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document.write( "point 1: (5,30)<BR>\n" );
document.write( "point 2: (15,30)<BR>\n" );
document.write( "x-intercept: (20,0) </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #683245 by </B><A HREF=/tutors/aboutme.mpl?userid=t0hierry><B>t0hierry(194)</B></A><img src=\"/images/stars/stars-09.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=t0hierry><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/cgi-bin/show-face.mpl?user=t0hierry><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=683245\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> y - 30 = a(x-5)(x-15) satisfies the first two conditions. Next we use the third constraint, which is\r<BR>\n" );
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document.write( "when x=20 we have 0 - 30 = a (20-5)(20-15) = 75a\r<BR>\n" );
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document.write( "or a = -30/75 = -10/25 = -0.4\r<BR>\n" );
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document.write( "I get y = -0.4 x^2 + 8x + 30\r<BR>\n" );
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document.write( "Let me know if this helps </SPAN>\n" );
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