document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1200591>Question 1200591</A>: <I><SPAN STYLE=\"word-break: break-all;\"> If p=6q-r and t=3q+r , find p in terms of r and t .\r<BR>\n" );
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document.write( "What I did : <BR>\n" );
document.write( "I first did r subject of formula:<BR>\n" );
document.write( "3q+r=t<BR>\n" );
document.write( "r=t-3q <BR>\n" );
document.write( "Then I substituted the r in the other equation :<BR>\n" );
document.write( "p=6q-(t-3q)<BR>\n" );
document.write( "p=6q-t+3q<BR>\n" );
document.write( "p=9q-t <BR>\n" );
document.write( "But the correct answer is :p=2t-3r, how is this supposed to be worked out please?  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #834766 by </B><A HREF=/tutors/aboutme.mpl?userid=greenestamps><B>greenestamps(13200)</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=834766\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <br><BR>\n" );
document.write( "The given information shows p and t in terms of q and r, and it asks for p in terms of r and t.  That means you need to eliminate q.<br><BR>\n" );
document.write( "You eliminated p to get p in terms of q and t.  You did that correctly -- but it was not what the question asked for.<br><BR>\n" );
document.write( "The given equations are<BR>\n" );
document.write( "p = 6q - r<BR>\n" );
document.write( "t = 3q + r<br><BR>\n" );
document.write( "By standard algebraic processes, to eliminate q you could solve one of the equations for q and substitute in the other equation.<br><BR>\n" );
document.write( "But seeing that one equation has \"6q\" and the other has \"3q\", you can do the elimination more easily.<br><BR>\n" );
document.write( "Multiply the second equation by 2 so that both equations have \"6q\":<br><BR>\n" );
document.write( "p = 6q - r<BR>\n" );
document.write( "2t = 6q + 2r<br><BR>\n" );
document.write( "Now solve one of the equations for \"6q\" and substitute the expression for 6q in the other equation.<br><BR>\n" );
document.write( "6q = p + r<BR>\n" );
document.write( "2t = (p+r)+2r = p + 3r<br><BR>\n" );
document.write( "And then solve for p<br><BR>\n" );
document.write( "2t = p + 3r<BR>\n" );
document.write( "p = 2t-3r<br><BR>\n" );
document.write( " </SPAN>\n" );
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