document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1103997>Question 1103997</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Kimberly bought 90 stamps in denominations of 41 cents, 58 cents and 75 cents. To test her daughter, who is taking  an algebra class, she said that she bought three times as many 41 cent stamps as 58 cent stamps and that the total cost of the stamps was $43.70. How many stamps of each denomination did she buy? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #718720 by </B><A HREF=/tutors/aboutme.mpl?userid=ankor@dixie-net.com><B>ankor@dixie-net.com(22740)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ankor@dixie-net.com><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=ankor@dixie-net.com><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=718720\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> let a = 41 cent stamps<BR>\n" );
document.write( "let b = 58 cent stamps<BR>\n" );
document.write( "let c = 75 cent stamps<BR>\n" );
document.write( ":<BR>\n" );
document.write( "write an equation for each statement<BR>\n" );
document.write( ";<BR>\n" );
document.write( "\"Kimberly bought 90 stamps\"<BR>\n" );
document.write( "a + b + c = 90<BR>\n" );
document.write( " three times as many 41 cent stamps as 58 cent stamps<BR>\n" );
document.write( "a = 3b<BR>\n" );
document.write( " and that the total cost of the stamps was $43.70.\"<BR>\n" );
document.write( ".41a + .58b + .75c = 43.70<BR>\n" );
document.write( " How many stamps of each denomination did she buy?<BR>\n" );
document.write( ":<BR>\n" );
document.write( "Replace a with 3b in the first equation<BR>\n" );
document.write( "3b + b + c = 90<BR>\n" );
document.write( "4b + c = 90<BR>\n" );
document.write( "c = (90-4b)  use this for substitution in the 3rd equation<BR>\n" );
document.write( ".41a + .58b + .75c = 43.70<BR>\n" );
document.write( ".41a + .58b + .75(90-4b) = 43.70<BR>\n" );
document.write( ".41a + .58b + 67.5 - 3b = 43.70<BR>\n" );
document.write( "combine like terms<BR>\n" );
document.write( ".41a - .58b - 3b = 43.70 - 67.50<BR>\n" );
document.write( ".41a - 2.42b = -23.80<BR>\n" );
document.write( "replace a with 3b<BR>\n" );
document.write( ".41(3b) - 2.42b = -23.80<BR>\n" );
document.write( "1.23b -2.42b = -23.80<BR>\n" );
document.write( "-1.19b = -23.80<BR>\n" );
document.write( "b = -23.80/-1.19<BR>\n" );
document.write( "b = +20 ea .58 cent stamps<BR>\n" );
document.write( "then<BR>\n" );
document.write( "3*20 = 60 ea .41 cent stamps<BR>\n" );
document.write( "and<BR>\n" );
document.write( "90 - 20 - 60 = 10 ea .75 cent stamps<BR>\n" );
document.write( ":<BR>\n" );
document.write( ":<BR>\n" );
document.write( "Check this in the 3rd equation<BR>\n" );
document.write( ".41(60) + .58(20) + .75(10) = <BR>\n" );
document.write( "24.60 + 11.69 + 7.50 = 43.70<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );