document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=253251>Question 253251</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A father's age is 3 more than four times the age of his son. If the product of their ages is 351, what is the father's age? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #185525 by </B><A HREF=/tutors/aboutme.mpl?userid=Greenfinch><B>Greenfinch(383)</B></A><img src=\"/images/stars/stars-10.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Greenfinch><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=Greenfinch><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=185525\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> If the son is Z years old, the father is 4Z + 3 years old<BR>\n" );
document.write( "Product is Z(4Z + 3) = 4Z^2 + 3Z = 351<BR>\n" );
document.write( "So 4Z^2 + 3Z - 351 = 0<BR>\n" );
document.write( "You can plug into the formula now or try factorisation<BR>\n" );
document.write( "Factors of 351 are 3x3x3x13<BR>\n" );
document.write( "3 x 13 gives 39 and 3 x 3 is 9, multiplied by the 4 from the z^2 term gives 36, difference 3 which is the Z term so<BR>\n" );
document.write( "(4Z + 39)(Z -  9)=0<BR>\n" );
document.write( "Z = -39 or 9<BR>\n" );
document.write( "So son's age is 9, father's age is 39 </SPAN>\n" );
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