document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=173613>Question 173613</A>This question is from textbook <A HREF=http://www.amazon.com/exec/obidos/ASIN/0321269470/algebrahomeworkh>Introductory Algebra</A><BR>\n" );
document.write( ": <I><SPAN STYLE=\"word-break: break-all;\"> Joe has a collection of nickels and dimes that is worth $6.00. If the number of dimes were doubled and the number of nickels were increased by 6, the value of the coins would be $9.90. How many dimes does he have? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #128495 by </B><A HREF=/tutors/aboutme.mpl?userid=gonzo><B>gonzo(654)</B></A><img src=\"/images/stars/stars-11.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=gonzo><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=128495\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> let n = number of nickels<BR>\n" );
document.write( "let d = number of dimes<BR>\n" );
document.write( "first equation is:<BR>\n" );
document.write( ".05*n + .1*d = 6.00<BR>\n" );
document.write( "-----<BR>\n" );
document.write( "second equation is:<BR>\n" );
document.write( ".05*(n+6) + .1*d*2 = 9.9<BR>\n" );
document.write( "expanding the second equation, we get:<BR>\n" );
document.write( ".05*n + .05*6 + .2*d = 9.9<BR>\n" );
document.write( "which becomes:<BR>\n" );
document.write( ".05*n + .3 + .2*d = 9.9<BR>\n" );
document.write( "subtract .3 from both sides of equation to get:<BR>\n" );
document.write( ".05*n + .2*d = 9.6<BR>\n" );
document.write( "-----<BR>\n" );
document.write( "2 equations to solve simultaneously are:<BR>\n" );
document.write( ".05*n + .1*d = 6.00<BR>\n" );
document.write( ".05*n + .2*d = 9.60<BR>\n" );
document.write( "-----<BR>\n" );
document.write( "subtract second equation from first to get:<BR>\n" );
document.write( ".1*d = 3.60<BR>\n" );
document.write( "d = 36<BR>\n" );
document.write( "-----<BR>\n" );
document.write( "number of dimes is 36<BR>\n" );
document.write( "substitute in first equation to get:<BR>\n" );
document.write( ".05*n + .1*(36) = 6<BR>\n" );
document.write( ".05*n + 3.6 = 6<BR>\n" );
document.write( "subtract 3.6 from both sides of equation to get:<BR>\n" );
document.write( ".05*n = 2.4<BR>\n" );
document.write( "divide both sides of equation by .05 to get:<BR>\n" );
document.write( " = 2.4/.05 = 48<BR>\n" );
document.write( "-----<BR>\n" );
document.write( "we have:<BR>\n" );
document.write( "number of dimes = 36<BR>\n" );
document.write( "number of nickels = 48<BR>\n" );
document.write( "-----<BR>\n" );
document.write( "substitute these values in second equation to get:<BR>\n" );
document.write( ".05*(48+6) + .1*36*2 = 9.9<BR>\n" );
document.write( ".05*(54) + 72*.1 = 9.9<BR>\n" );
document.write( "2.7 + 7.2 = 9.9<BR>\n" );
document.write( "9.9 = 9.9<BR>\n" );
document.write( "-----<BR>\n" );
document.write( "equations are good.<BR>\n" );
document.write( "answer to the question is:<BR>\n" );
document.write( "he has 36 dimes.<BR>\n" );
document.write( "-----<BR>\n" );
document.write( "-----<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );