document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=550138>Question 550138</A>: <I><SPAN STYLE=\"word-break: break-all;\"> We have 4 hippos and we weigh them in pairs. After<BR>\n" );
document.write( "weighing all possible pairs, we obtain the following list of<BR>\n" );
document.write( "the weights of all pairs. Here is the list:<BR>\n" );
document.write( "{356,362,374,374,386,392}<BR>\n" );
document.write( "What is the sum of the weights of all the 4 hippos? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #358505 by </B><A HREF=/tutors/aboutme.mpl?userid=ankor@dixie-net.com><B>ankor@dixie-net.com(22740)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ankor@dixie-net.com><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=ankor@dixie-net.com><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=358505\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> We have 4 hippos and we weigh them in pairs.<BR>\n" );
document.write( " After weighing all possible pairs, we obtain the following list of<BR>\n" );
document.write( "the weights of all pairs.<BR>\n" );
document.write( " Here is the list:<BR>\n" );
document.write( "{356, 362, 374, 374, 386, 392}<BR>\n" );
document.write( "4 hippos a,b,c,d<BR>\n" );
document.write( ";<BR>\n" );
document.write( "a+b = 356<BR>\n" );
document.write( "a+c = 362<BR>\n" );
document.write( "a+d = 374<BR>\n" );
document.write( "b+c = 374<BR>\n" );
document.write( "b+d = 386<BR>\n" );
document.write( "c+d = 392<BR>\n" );
document.write( ":<BR>\n" );
document.write( "Using the 1st two equations<BR>\n" );
document.write( "a + 0 + c = 362<BR>\n" );
document.write( "a + b + 0 = 356<BR>\n" );
document.write( "-----------------subtraction eliminates a<BR>\n" );
document.write( "   -b + c = 6<BR>\n" );
document.write( "c = (b+6)<BR>\n" );
document.write( "using the 4th equation<BR>\n" );
document.write( "b + c = 374<BR>\n" );
document.write( "replace c with (b+6)<BR>\n" );
document.write( "b + (b+6) = 374<BR>\n" );
document.write( "2b = 374-6<BR>\n" );
document.write( "2b = 368<BR>\n" );
document.write( "b = 368/2<BR>\n" );
document.write( "b = 184 kg is b's weight<BR>\n" );
document.write( "then using the 1st equation<BR>\n" );
document.write( "a + 184 = 356<BR>\n" );
document.write( "a = 356 - 184<BR>\n" );
document.write( "a = 172 kg is a's weight<BR>\n" );
document.write( ":<BR>\n" );
document.write( "Find c<BR>\n" );
document.write( "c = 184 + 6<BR>\n" );
document.write( "c = 190 kg  is c's weight<BR>\n" );
document.write( ":<BR>\n" );
document.write( "find d<BR>\n" );
document.write( "d + 190 = 392<BR>\n" );
document.write( "d = 392 - 190<BR>\n" );
document.write( "d = 202 kg is d's weight<BR>\n" );
document.write( "\"<BR>\n" );
document.write( "find the sum<BR>\n" );
document.write( "a = 172<BR>\n" );
document.write( "b = 184<BR>\n" );
document.write( "c = 190<BR>\n" );
document.write( "d = 202<BR>\n" );
document.write( "--------<BR>\n" );
document.write( "sum 748 kg<BR>\n" );
document.write( " <BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );