document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=769894>Question 769894</A>: <I><SPAN STYLE=\"word-break: break-all;\"> the radius, r, of a circle has been increased by k. both r and k are measured in the same units. write a formula for the area of the new circle . expand and simplify\r<BR>\n" );
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document.write( "r= r+k<BR>\n" );
document.write( "A=pi*r^2<BR>\n" );
document.write( " = pi*(r+k)^2<BR>\n" );
document.write( "=pi*(r^2+2rk+k^2)\r<BR>\n" );
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document.write( "is this correct or something's wrong? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #469108 by </B><A HREF=/tutors/aboutme.mpl?userid=josgarithmetic><B>josgarithmetic(39617)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=josgarithmetic><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/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=469108\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Original radius, r.<BR>\n" );
document.write( "Increased radius, r+k.\r<BR>\n" );
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document.write( "For this situation, because you are not writing some kind of computer code, do NOT say r=r+k.  \r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=A%5B0%5D=pi%2Ar%5E2 ALIGN=MIDDLE  ALT=\"A%5B0%5D=pi%2Ar%5E2\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "The subscript is for original or initial.\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=A%5Bn%5D=pi%2A%28r%2Bk%29%5E2 ALIGN=MIDDLE  ALT=\"A%5Bn%5D=pi%2A%28r%2Bk%29%5E2\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "The new area when radius increases by k.\r<BR>\n" );
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document.write( "But your work in your last two steps is good.  The new area IS <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=pi%2A%28r%5E2%2B2rk%2Bk%5E2%29 ALIGN=MIDDLE  ALT=\"pi%2A%28r%5E2%2B2rk%2Bk%5E2%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >.<BR>\n" );
document.write( "You just cannot say <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=A=pi%2Ar%5E2=pi%2A%28r%2Bk%29%5E2 ALIGN=MIDDLE  ALT=\"A=pi%2Ar%5E2=pi%2A%28r%2Bk%29%5E2\"   DISABLED_style= \"max-width:90%; height:auto;\" > because it is wrong. </SPAN>\n" );
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