document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=474986>Question 474986</A>: <I><SPAN STYLE=\"word-break: break-all;\"> a spring stretches to 22cm with a 70g weight attached to the end. with a 105g weight attached, it stretches to 27cm. which equation models the distance y the spring stretches with weight x attached to it?<BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #325715 by </B><A HREF=/tutors/aboutme.mpl?userid=htmentor><B>htmentor(1343)</B></A><img src=\"/images/stars/stars-12.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=htmentor><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=htmentor><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=325715\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> a spring stretches to 22cm with a 70g weight attached to the end. with a 105g weight attached, it stretches to 27cm. which equation models the distance y the spring stretches with weight x attached to it?<BR>\n" );
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document.write( "The equation has the form y = mx + b.<BR>\n" );
document.write( "Given the two points (70,22) and (105,27) we have two equations and two unknowns<BR>\n" );
document.write( "22 =  70m + b [1]<BR>\n" );
document.write( "27 = 105m + b [2]<BR>\n" );
document.write( "Subtract [1] from [2]<BR>\n" );
document.write( "5 = 35m<BR>\n" );
document.write( "This gives m = 1/7<BR>\n" );
document.write( "Now substitute this value for m into either of the two equations ([1]):<BR>\n" );
document.write( "22 = 70*1/7 + b<BR>\n" );
document.write( "22 = 10 + b<BR>\n" );
document.write( "b = 12<BR>\n" );
document.write( "So the equation is y = x/7 + 12 </SPAN>\n" );
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