document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=995744>Question 995744</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A girl is twice as old as her sister. Four year hence, the product of their ages will be 160. find their present ages  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #614406 by </B><A HREF=/tutors/aboutme.mpl?userid=ptaylor><B>ptaylor(2198)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ptaylor><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=ptaylor><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=614406\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <BR>\n" );
document.write( "Let x = sisters present age; 4 yrs hence her age will be x+4<BR>\n" );
document.write( "Then 2x= other girls present age; 4 years hence her age will be 2x+4<BR>\n" );
document.write( "Sooooo<BR>\n" );
document.write( "(x+4)(2x+4)=160<BR>\n" );
document.write( "Using FOIL we have 2x^2+4x+8x+16=160<BR>\n" );
document.write( "2x^2+12x+16=160. divide each term by 2<BR>\n" );
document.write( "x^2+6x+8=80 or<BR>\n" );
document.write( "x^2+6x-72=0  quadratic in standard form and it can be factored<BR>\n" );
document.write( "(x+12)(x-6)=0<BR>\n" );
document.write( "x=-12-----no good can't have negative age<BR>\n" );
document.write( "x=6-----answer<BR>\n" );
document.write( "sisters age is 6<BR>\n" );
document.write( "girls age is 12<BR>\n" );
document.write( "CK<BR>\n" );
document.write( "(6+4)(12+4)=160<BR>\n" );
document.write( "160=160\r<BR>\n" );
document.write( "\n" );
document.write( "hope this helps----ptaylor </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );