document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1016995>Question 1016995</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Please Help. Show work Thanks in advance.\r<BR>\n" );
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document.write( "A person's systolic blood pressure, which is measured in millimeters of mercury (mm Hg), depends on a person's age, in years. The equation:\r<BR>\n" );
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document.write( "P=0.007y^2&#8722;0.03y+122<BR>\n" );
document.write( "P=0.007y^2-0.03y+122\r<BR>\n" );
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document.write( " gives a person's blood pressure, P<BR>\n" );
document.write( "P<BR>\n" );
document.write( ", at age y<BR>\n" );
document.write( "y<BR>\n" );
document.write( " years.\r<BR>\n" );
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document.write( " A.) Find the systolic pressure, to the nearest tenth of a millimeter, for a person of age 40 years.\r<BR>\n" );
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document.write( " B.) If a person's systolic pressure is 132.54 mm Hg, what is their age (rounded to the nearest single year)?\r<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 #633328 by </B><A HREF=/tutors/aboutme.mpl?userid=macston><B>macston(5194)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=macston><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=macston><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=633328\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> .<BR>\n" );
document.write( "P=0.007y^2-0.03y+122<BR>\n" );
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document.write( " A.) Find the systolic pressure, to the nearest tenth of a millimeter, for a person of age 40 years.<BR>\n" );
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document.write( "Replace y with 40 and solve for P.<BR>\n" );
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document.write( "P=0.007(40^2)-0.03(40)+122<BR>\n" );
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document.write( " B.) If a person's systolic pressure is 132.54 mm Hg, what is their age (rounded to the nearest single year)?<BR>\n" );
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document.write( "Replace P with 132.54 and solve for y:<BR>\n" );
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document.write( "P=0.007y^2-0.03y+122<BR>\n" );
document.write( "132.54=0.007y^2-0.03y+122 . Subtract 132.54 from each side.<BR>\n" );
document.write( "0=0.007y^2+0.03y-10.54 . Multiply each side by 1000.<BR>\n" );
document.write( "0=7y^2+30y-10540 . <BR>\n" );
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document.write( " <TR><TD  ALIGN=MIDDLE>Solved by <A  rel=nofollow HREF=http://wiki.algebra.com/index.php/Tutoring_-_pluggable_solvers>pluggable</A> solver: <A  rel=nofollow HREF=quadratic.solver>SOLVE quadratic equation with variable</A></TD></TR>\n" );
document.write( "<TR><TD  ALIGN=LEFT>Quadratic equation <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=ay%5E2%2Bby%2Bc=0 ALIGN=MIDDLE  ALT=\"ay%5E2%2Bby%2Bc=0\"   DISABLED_style= \"max-width:90%; height:auto;\" > (in our case <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=7y%5E2%2B30y%2B-10540+=+0 ALIGN=MIDDLE  ALT=\"7y%5E2%2B30y%2B-10540+=+0\"   DISABLED_style= \"max-width:90%; height:auto;\" >) has the following solutons:<BR>\n" );
document.write( "  <BR>\n" );
document.write( "  <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=y%5B12%5D+=+%28b%2B-sqrt%28+b%5E2-4ac+%29%29%2F2%5Ca ALIGN=MIDDLE  ALT=\"y%5B12%5D+=+%28b%2B-sqrt%28+b%5E2-4ac+%29%29%2F2%5Ca\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
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document.write( "  For these solutions to exist, the <U>discriminant</U> <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=b%5E2-4ac ALIGN=MIDDLE  ALT=\"b%5E2-4ac\"   DISABLED_style= \"max-width:90%; height:auto;\" > should not be a negative number.<BR>\n" );
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document.write( "  First, we need to compute the discriminant <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=b%5E2-4ac ALIGN=MIDDLE  ALT=\"b%5E2-4ac\"   DISABLED_style= \"max-width:90%; height:auto;\" >: <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=b%5E2-4ac=%2830%29%5E2-4%2A7%2A-10540=296020 ALIGN=MIDDLE  ALT=\"b%5E2-4ac=%2830%29%5E2-4%2A7%2A-10540=296020\"   DISABLED_style= \"max-width:90%; height:auto;\" >.<BR>\n" );
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document.write( "  Discriminant d=296020 is greater than zero. That means that there are two solutions: <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+x%5B12%5D+=+%28-30%2B-sqrt%28+296020+%29%29%2F2%5Ca ALIGN=MIDDLE  ALT=\"+x%5B12%5D+=+%28-30%2B-sqrt%28+296020+%29%29%2F2%5Ca\"   DISABLED_style= \"max-width:90%; height:auto;\" >.<BR>\n" );
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document.write( "    <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=y%5B1%5D+=+%28-%2830%29%2Bsqrt%28+296020+%29%29%2F2%5C7+=+36.719800028893 ALIGN=MIDDLE  ALT=\"y%5B1%5D+=+%28-%2830%29%2Bsqrt%28+296020+%29%29%2F2%5C7+=+36.719800028893\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "    <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=y%5B2%5D+=+%28-%2830%29-sqrt%28+296020+%29%29%2F2%5C7+=+-41.0055143146072 ALIGN=MIDDLE  ALT=\"y%5B2%5D+=+%28-%2830%29-sqrt%28+296020+%29%29%2F2%5C7+=+-41.0055143146072\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
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document.write( "    Quadratic expression <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=7y%5E2%2B30y%2B-10540 ALIGN=MIDDLE  ALT=\"7y%5E2%2B30y%2B-10540\"   DISABLED_style= \"max-width:90%; height:auto;\" > can be factored:<BR>\n" );
document.write( "  <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=7y%5E2%2B30y%2B-10540+=+7%28y-36.719800028893%29%2A%28y--41.0055143146072%29 ALIGN=MIDDLE  ALT=\"7y%5E2%2B30y%2B-10540+=+7%28y-36.719800028893%29%2A%28y--41.0055143146072%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "  Again, the answer is: 36.719800028893, -41.0055143146072.\n" );
document.write( "Here's your graph:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+7%2Ax%5E2%2B30%2Ax%2B-10540+%29 ALIGN=MIDDLE  ALT=\"graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+7%2Ax%5E2%2B30%2Ax%2B-10540+%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ></TD></TR>\n" );
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document.write( "Since negative age does not work, the person's age is 36.7 years.<BR>\n" );
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document.write( "ANSWER B: The person is 37 years old.<BR>\n" );
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