document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=469796>Question 469796</A>: <I><SPAN STYLE=\"word-break: break-all;\">  I just got my SAT test book back and there is one problem that I do not know how to do:\r<BR>\n" );
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document.write( "The product of a and b is equal to x and the sum of a and b is equal to y. If x and y are positive numbers, what is 1/a + 1/b in terms of x and y.  The answer is y/x but I don't understand how to get that answer. Help!\r<BR>\n" );
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document.write( "Thanks. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #322274 by </B><A HREF=/tutors/aboutme.mpl?userid=ccs2011><B>ccs2011(207)</B></A><img src=\"/images/stars/stars-09.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ccs2011><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=ccs2011><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=322274\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Start with the given <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=1%2Fa+%2B+1%2Fb ALIGN=MIDDLE  ALT=\"1%2Fa+%2B+1%2Fb\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Combine this into 1 fraction, find common denominator<BR>\n" );
document.write( "common denominator is ab<BR>\n" );
document.write( "--> <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=1%2Fa+%2B+1%2Fb+=+%28b%2Fab%29%2B%28a%2Fab%29+=+%28a%2Bb%29%2Fab ALIGN=MIDDLE  ALT=\"1%2Fa+%2B+1%2Fb+=+%28b%2Fab%29%2B%28a%2Fab%29+=+%28a%2Bb%29%2Fab\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Then use substitution:<BR>\n" );
document.write( "we know a+b = y and ab = x<BR>\n" );
document.write( "--> <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28a%2Bb%29%2Fab+=+y%2Fx ALIGN=MIDDLE  ALT=\"%28a%2Bb%29%2Fab+=+y%2Fx\"   DISABLED_style= \"max-width:90%; height:auto;\" > </SPAN>\n" );
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