document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=987202>Question 987202</A>: <I><SPAN STYLE=\"word-break: break-all;\"> PLEASE PLEASE HELP I can't seem to figure out how to do these four problems.\r<BR>\n" );
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document.write( "My kids’ bathtub is being drained. Since it is an ordinary tub, it can be modeled by the function  <BR>\n" );
document.write( "V(t) = -15t + 45 where V(t) is the volume of the tub in gallons and t is the time that has passed in minutes.\r<BR>\n" );
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document.write( "1.Based on the function V(t) = -15t + 45, when will the tub be half full?\r<BR>\n" );
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document.write( "2.What is the practical domain in this problem?  Use appropriate notation in your answer.\r<BR>\n" );
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document.write( "3.What is the practical range?  Use the appropriate notation in your answer.\r<BR>\n" );
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document.write( "4.My tub is a garden tub. When I drain it I can model the volume of water in it by <BR>\n" );
document.write( "v(T) = -20T + 50 where v(T) is the volume of the tub in gallons and T is the time that has passed <BR>\n" );
document.write( "in minutes.  Given all this, which tub drains faster, my kids’ tub, or mine? Explain your reasoning. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #607975 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=607975\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <font face=\"Times New Roman\" size=\"+2\">\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=\"/cgi-bin/rendertex.cgi?\LARGE \ \ \ \ \ \ \ \ \ \ V(t)\ =\ -15t\ +\ 45\">\r<BR>\n" );
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document.write( "Since this model gives the volume of water in the tub over time as it is draining, the value of the function at time zero must be the capacity of a full tub.  Substitute zero for <IMG STYLE=\"max-width:80%;\" SRC=\"/cgi-bin/rendertex.cgi?\Large t\"> and solve for <IMG STYLE=\"max-width:80%;\" SRC=\"/cgi-bin/rendertex.cgi?\Large V(0)\">, the volume of water in a full tub.\r<BR>\n" );
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document.write( "Once you know the volume of a full tub, you can divide that number by 2 to find the volume of a half-full tub.\r<BR>\n" );
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document.write( "Set <IMG STYLE=\"max-width:80%;\" SRC=\"/cgi-bin/rendertex.cgi?\Large -15t\ +\ 45\"> equal to the volume of a half full tub and solve for <IMG STYLE=\"max-width:80%;\" SRC=\"/cgi-bin/rendertex.cgi?\Large t_{1/2}\">, the time at which the tub will be half full.\r<BR>\n" );
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document.write( "Since the Volume function is a linear function, there is another way to do this.  Set the function equal to zero and then solve for <IMG STYLE=\"max-width:80%;\" SRC=\"/cgi-bin/rendertex.cgi?\Large t_e\">,  the time when the tub will be empty.  Since the function is linear, the tub will be half-empty when half the time to empty it completely has passed.  I recommend that you solve this both ways to verify.\r<BR>\n" );
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document.write( "Part of your particular problem with mathematics is that you either cannot, or refuse to, read and follow written instructions.  I refer to the very clear instruction on the page where you posted these questions that says \"One problem per submission\".\r<BR>\n" );
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document.write( "John<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=\"/cgi-bin/rendertex.cgi?\LARGE e^{i\pi}\ +\ 1\ =\ 0\"><BR>\n" );
document.write( "My calculator said it, I believe it, that settles it\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=\"/cgi-bin/rendertex.cgi?\Large \ \\r\"> </SPAN>\n" );
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