document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=857604>Question 857604</A>: <I><SPAN STYLE=\"word-break: break-all;\"> a 7cm by 10cm picture is mounted on a board with an equal border surrounding the picture. the area of the board is 208cm.  what is width of border?  helping son with quadratic equations and stumped why answer is 3? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #516748 by </B><A HREF=/tutors/aboutme.mpl?userid=mananth><B>mananth(16946)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=mananth><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=mananth><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=516748\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> a 7cm by 10cm picture is mounted on a board with an equal border surrounding the picture. the area of the board is 208cm.  what is width of border?  helping son with quadratic equations and stumped why answer is 3?\r<BR>\n" );
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document.write( "Area of picture = 7*10 = 70 cm^2\r<BR>\n" );
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document.write( "Let width be x on either side of length and width\r<BR>\n" );
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document.write( "length of board = 10+2x<BR>\n" );
document.write( "Width of board = 7+2x\r<BR>\n" );
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document.write( "Area of board = 208 cm^2\r<BR>\n" );
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document.write( "Area = L*W\r<BR>\n" );
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document.write( "(10+2x)(7+2x) = 208\r<BR>\n" );
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document.write( "70+20x+14x+4x^2=208\r<BR>\n" );
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document.write( "4x^2+34x+70 = 208\r<BR>\n" );
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document.write( "4x^2+34x-138=0<BR>\n" );
document.write( "/2\r<BR>\n" );
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document.write( "2x^2+17x-69=0\r<BR>\n" );
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document.write( "2x^2+23x-6x-69=0\r<BR>\n" );
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document.write( "2x(x+11.5)-6(x+11.5)=0\r<BR>\n" );
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document.write( "(2x-6)(x+11.5)=0\r<BR>\n" );
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document.write( "either 2x=6 OR x=-11.5<BR>\n" );
document.write( "Ignore negative\r<BR>\n" );
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document.write( "2x=6<BR>\n" );
document.write( "x= 3 cm\r<BR>\n" );
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document.write( "You can solve by squaring method or formula method.\r<BR>\n" );
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document.write( "Formula method\r<BR>\n" );
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document.write( "Find the roots of the equation by quadratic formula							<BR>\n" );
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document.write( "a=	2	,	b=	17	,	c=	-69<BR>\n" );
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document.write( "b^2-4ac=	289	+	552				<BR>\n" );
document.write( "b^2-4ac=	841						<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%09sqrt%28%09841%09%29=%0929%09 ALIGN=MIDDLE  ALT=\"%09sqrt%28%09841%09%29=%0929%09\"   DISABLED_style= \"max-width:90%; height:auto;\" >		<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x=%28-b%2B-sqrt%28b%5E2-4ac%29%29%2F%282a%29 ALIGN=MIDDLE  ALT=\"x=%28-b%2B-sqrt%28b%5E2-4ac%29%29%2F%282a%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >							<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x1=%28-b%2Bsqrt%28b%5E2-4ac%29%29%2F%282a%29 ALIGN=MIDDLE  ALT=\"x1=%28-b%2Bsqrt%28b%5E2-4ac%29%29%2F%282a%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >							<BR>\n" );
document.write( "x1=(	-17	+	29	)/	4		<BR>\n" );
document.write( "x1=	3.00						<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x2=%28-b-sqrt%28b%5E2-4ac%29%29%2F%282a%29 ALIGN=MIDDLE  ALT=\"x2=%28-b-sqrt%28b%5E2-4ac%29%29%2F%282a%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >							<BR>\n" );
document.write( "x2=(	-17	-29	) /	4			<BR>\n" );
document.write( "x2=	-11.50						<BR>\n" );
document.write( "Ignore negative value							<BR>\n" );
document.write( "x=3 cm\r<BR>\n" );
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document.write( " </SPAN>\n" );
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