document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=195416>Question 195416</A>: <I><SPAN STYLE=\"word-break: break-all;\"> if x+y=2a and x-y=2b, what is the value of xy? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #146550 by </B><A HREF=/tutors/aboutme.mpl?userid=anantha><B>anantha(86)</B></A><img src=\"/images/stars/stars-08.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=anantha><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=146550\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> sol:<BR>\n" );
document.write( " x+y=2a<BR>\n" );
document.write( " x-y=2b<BR>\n" );
document.write( "adding these two equations<BR>\n" );
document.write( " x+y=2a<BR>\n" );
document.write( " x-y=2b<BR>\n" );
document.write( "-----------<BR>\n" );
document.write( "2x+0y=2a+2b<BR>\n" );
document.write( " 2x=2(a+b)<BR>\n" );
document.write( "dividing by 2 on both sides we get<BR>\n" );
document.write( "2x/2=2(a+b)/2<BR>\n" );
document.write( "x=a+b<BR>\n" );
document.write( "substitute this value in equation 1<BR>\n" );
document.write( "(a+b)+y=2a<BR>\n" );
document.write( "a+b+y=2a<BR>\n" );
document.write( "subtracting a on both sides<BR>\n" );
document.write( "a+b+y-a=2a-a<BR>\n" );
document.write( "b+y=a<BR>\n" );
document.write( "y=a-b(i.e;subtract b on both sides)<BR>\n" );
document.write( "xy=(a+b)(a-b)<BR>\n" );
document.write( "xy=a^2-b^2(i.e;(a+b)(a-b)=a*a-a*b+b*a-b*b=a^2-ab+ab-b^2=a^2-b^2)<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );