document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1152216>Question 1152216</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Kate makes a donation to a charitable organisation on a monthly basis. Her monthly donation is directly proportional to her monthy savings. If she saves $900 and $1200 in January ano February respectively,her donation increases by $35 from January to February. Find the amount of money she donates to the charitable organisation in each of the two months. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #774191 by </B><A HREF=/tutors/aboutme.mpl?userid=Theo><B>Theo(13342)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Theo><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=Theo><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=774191\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> d = donation<BR>\n" );
document.write( "s = savings.<BR>\n" );
document.write( "in january, savings = 900.<BR>\n" );
document.write( "in february, savings = 1200.<BR>\n" );
document.write( "in january, donation = d<BR>\n" );
document.write( "in february donation = d + 35<BR>\n" );
document.write( "since they are directly proportional, you get:<BR>\n" );
document.write( "d / 900 = (d + 35) / 1200<BR>\n" );
document.write( "cross multiply to get:<BR>\n" );
document.write( "d * 1200 = 900 * (d + 35)<BR>\n" );
document.write( "simplify to get:<BR>\n" );
document.write( "d * 1200 = 900 * d + 35 * 900<BR>\n" );
document.write( "subtract 900 * d from both sides of the equation and simplify to get:<BR>\n" );
document.write( "300 * d = 31500<BR>\n" );
document.write( "solve for d to get:<BR>\n" );
document.write( "d = 31500 / 300 = 105<BR>\n" );
document.write( "d + 35 is therefore equal to 140<BR>\n" );
document.write( "you get:<BR>\n" );
document.write( "d / 900 = (d + 35) / 1200 becomes 105 / 900 = 140 / 1200.<BR>\n" );
document.write( "cross multiply to get:<BR>\n" );
document.write( "105 * 1200 = 900 * 140<BR>\n" );
document.write( "simplify to get:<BR>\n" );
document.write( "126000 = 126000.<BR>\n" );
document.write( "this confirms that her monthly donation is directly proportional to her savings.<BR>\n" );
document.write( "the ratio in january is 105 / 900 = <BR>\n" );
document.write( "the amount of money that she donates to the charitable organization in each of the two months is 105 in january and 140 in february.<BR>\n" );
document.write( "you can also confirm this by using the directly porportional formula of y = k * x<BR>\n" );
document.write( "when x = 105, y = 900<BR>\n" );
document.write( "solve for k to get k = 900 / 105 = 8.571428571.<BR>\n" );
document.write( "when x = 140, y = k * 140 = 8.571428i571 * 140 = 1200.<BR>\n" );
document.write( "your solution is that she donates 105 in january and 140 in february to the charitable organization.<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );