document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1150741>Question 1150741</A>: <I><SPAN STYLE=\"word-break: break-all;\"> If a+b=-3 and b-c=6, find he value of 2a^2-3b^2+c^2.  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #772161 by </B><A HREF=/tutors/aboutme.mpl?userid=greenestamps><B>greenestamps(13206)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=greenestamps><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=greenestamps><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=772161\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <br><BR>\n" );
document.write( "We have three unknowns and only two equations, so it looks as if there is not enough information to solve the problem.<br><BR>\n" );
document.write( "However, the problem does not ask us to solve for a, b, and c.  It only asks us to find the value of 2a^2-3b^2+c^2.  It turns out the problem is contrived so that it is possible to do that.<br><BR>\n" );
document.write( "One piece of given information relates the values of a and b; the other relates the values of b and c.  The common variable there is b.  So use those pieces of information to find expressions for a and c in terms of b and substitute them in the expression to be evaluated.  It will turn out that all the variable terms cancel out, leaving you with a numerical value for the expression.<br><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=a%2Bb+=+-3 ALIGN=MIDDLE  ALT=\"a%2Bb+=+-3\"   DISABLED_style= \"max-width:90%; height:auto;\" >  -->  <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=a+=+-b-3 ALIGN=MIDDLE  ALT=\"a+=+-b-3\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=b-c+=+6 ALIGN=MIDDLE  ALT=\"b-c+=+6\"   DISABLED_style= \"max-width:90%; height:auto;\" >  -->  <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=c+=+b-6 ALIGN=MIDDLE  ALT=\"c+=+b-6\"   DISABLED_style= \"max-width:90%; height:auto;\" ><br><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=2a%5E2-3b%5E2%2Bc%5E2+=+2%28-b-3%29%5E2-3b%5E2%2B%28b-6%29%5E2 ALIGN=MIDDLE  ALT=\"2a%5E2-3b%5E2%2Bc%5E2+=+2%28-b-3%29%5E2-3b%5E2%2B%28b-6%29%5E2\"   DISABLED_style= \"max-width:90%; height:auto;\" ><br><BR>\n" );
document.write( "Expand and simplify to find the answer....<br><BR>\n" );
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