document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=120877>Question 120877</A>: <I><SPAN STYLE=\"word-break: break-all;\"> a park planner has sketched a rectanular park in the first quadrent of a coordinate grid. wo sides of the park lie on the x- and y-axes. a trapezoidal flower bed will be bounded by the line y=x+7, the x-axis, and the vertical lines x=1 and x=a, where a is greater than 1. The areaA of the trapezoid is modeled by A=1/2a squared+7a-15/2. assume the lengthsamong the axes are measured in meters. For what value of a will the trapezoid have an area of 25 meters? use the quadratic formula to find the answer </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #88716 by </B><A HREF=/tutors/aboutme.mpl?userid=solver91311><B>solver91311(24713)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=solver91311><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=solver91311><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=88716\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=A=%28%28a-1%29%28%28a%2B7%29%2B8%29%29%2F2 ALIGN=MIDDLE  ALT=\"A=%28%28a-1%29%28%28a%2B7%29%2B8%29%29%2F2\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=A=%28%28a-1%29%28a%2B15%29%29%2F2 ALIGN=MIDDLE  ALT=\"A=%28%28a-1%29%28a%2B15%29%29%2F2\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=A=%28a%5E2%2B14a-15%29%2F2 ALIGN=MIDDLE  ALT=\"A=%28a%5E2%2B14a-15%29%2F2\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "You have an expression in terms of the variable a that represents the area, so all you need to do is set that expression equal to 25 and solve.\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=A=%281%2F2%29a%5E2%2B7a-%2815%2F2%29 ALIGN=MIDDLE  ALT=\"A=%281%2F2%29a%5E2%2B7a-%2815%2F2%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%281%2F2%29a%5E2%2B7a-%2815%2F2%29=25 ALIGN=MIDDLE  ALT=\"%281%2F2%29a%5E2%2B7a-%2815%2F2%29=25\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "Since fractional coefficients will be a pain when you evaluate the quadratic formula, multiply through by 2:\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=a%5E2%2B7a-15=50 ALIGN=MIDDLE  ALT=\"a%5E2%2B7a-15=50\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "Now add -50 to both sides to get the equation in standard form:\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=a%5E2%2B14a-65=0 ALIGN=MIDDLE  ALT=\"a%5E2%2B14a-65=0\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+ ALIGN=MIDDLE  ALT=\"x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" > <BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x+=+%28-14+%2B-+sqrt%28+14%5E2-4%2A1%2A%28-65%29+%29%29%2F%282%29+ ALIGN=MIDDLE  ALT=\"x+=+%28-14+%2B-+sqrt%28+14%5E2-4%2A1%2A%28-65%29+%29%29%2F%282%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" > <BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x+=+%28-14+%2B-+sqrt%28+456+%29%29%2F%282%29+ ALIGN=MIDDLE  ALT=\"x+=+%28-14+%2B-+sqrt%28+456+%29%29%2F%282%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" > <BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x+=+%28-14+%2B-+2sqrt%28+114+%29%29%2F%282%29+ ALIGN=MIDDLE  ALT=\"x+=+%28-14+%2B-+2sqrt%28+114+%29%29%2F%282%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" > <BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x+=+-7%2B-+sqrt%28+114+%29+ ALIGN=MIDDLE  ALT=\"x+=+-7%2B-+sqrt%28+114+%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=-7-sqrt%28114%29 ALIGN=MIDDLE  ALT=\"-7-sqrt%28114%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > can be excluded because it is clearly less than zero and the problem conditions demand a > 1.  So the correct and only answer is:\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x=-7%2Bsqrt%28114%29 ALIGN=MIDDLE  ALT=\"x=-7%2Bsqrt%28114%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >, roughly 3.7\r<BR>\n" );
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document.write( "Should you believe me?  Not without checking, you shouldn't.\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=A=%28%28%28-7%2Bsqrt%28114%29%29-1%29%28%28%28-7%2Bsqrt%28114%29%29%2B7%29%2B8%29%29%2F2 ALIGN=MIDDLE  ALT=\"A=%28%28%28-7%2Bsqrt%28114%29%29-1%29%28%28%28-7%2Bsqrt%28114%29%29%2B7%29%2B8%29%29%2F2\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=A=%28sqrt%28114%29-8%29%28sqrt%28114%29%2B8%29%2F2=%28114-64%29%2F2=50%2F2=25 ALIGN=MIDDLE  ALT=\"A=%28sqrt%28114%29-8%29%28sqrt%28114%29%2B8%29%2F2=%28114-64%29%2F2=50%2F2=25\"   DISABLED_style= \"max-width:90%; height:auto;\" > Answer checks </SPAN>\n" );
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