document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1010182>Question 1010182</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Factor- 36x^2 - 81 .  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #625648 by </B><A HREF=/tutors/aboutme.mpl?userid=Theo><B>Theo(13342)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Theo><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=Theo><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=625648\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> start with 36x^2 - 81 = y<BR>\n" );
document.write( "set y = 0 to get 36x^2 - 81 = 0<BR>\n" );
document.write( "add 81 to both sides of this equation to get 36x^2 = 81<BR>\n" );
document.write( "divide both sides of this equation to get x^2 = 81/36<BR>\n" );
document.write( "simplify to get x^2 = 2.25<BR>\n" );
document.write( "take the square root of both sides of the equation to get x = 1.5 or x = -1.5\r<BR>\n" );
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document.write( "this is also in the form of (a^2 - b^2) = (a + b) * (a - b)\r<BR>\n" );
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document.write( "a^2 = 36x^2 so a = 6x<BR>\n" );
document.write( "b^2 = 81 so b = 9\r<BR>\n" );
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document.write( "you get (36x^2 - 81) = ((6x)^2 - 9^2) = (6x + 9) * (6x - 9)\r<BR>\n" );
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document.write( "set each of these factors equal to 0 and you get 6x = -9 and 6x = 9\r<BR>\n" );
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document.write( "solve for x in each to get x = -1.5 and x = 1.5\r<BR>\n" );
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document.write( "you could also have used the quadratic formula which would have gotten you the same answer.\r<BR>\n" );
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document.write( "the equation of 36x^2 - 81 = 0 yields:<BR>\n" );
document.write( "a = 36<BR>\n" );
document.write( "b = 0<BR>\n" );
document.write( "c = -81\r<BR>\n" );
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document.write( "the quadratic formula is x = (-b plus or minus sqrt(b^2-4ac)) divided by 2a.\r<BR>\n" );
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document.write( "solve it and you will see that x = plus or minus 1.5.\r<BR>\n" );
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