document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=713345>Question 713345</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A wild bird seed mix is made by combining 150 lb of millet seed costing $0.40 per pound with sunflower seeds costing $1.30 per pound. How many pounds of sunflower seeds are needed to make a mixture that costs $0.70 per pound?<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 #438455 by </B><A HREF=/tutors/aboutme.mpl?userid=josgarithmetic><B>josgarithmetic(39617)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=josgarithmetic><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=438455\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Solve in general first, especially if you have other problems like that one.\r<BR>\n" );
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document.write( "ASSIGN VARIABLES TO ALL QUANTITIES<BR>\n" );
document.write( "L, the lower concentration of available material, $0.40/pound<BR>\n" );
document.write( "H, the higher concentration of available material, $1.30/pound<BR>\n" );
document.write( "T, the target concentration of resulting mixture, $0.70/pound<BR>\n" );
document.write( "x, the amount of lower concentrated material to use, 150 pounds<BR>\n" );
document.write( "y, the amount of higher concentrated material to use,  UNKNOWN\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=highlight%28%28Lx%2ByH%29%2F%28x%2By%29=T%29 ALIGN=MIDDLE  ALT=\"highlight%28%28Lx%2ByH%29%2F%28x%2By%29=T%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "That can be partly changed by multiplying both sides by x+y to get  <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=Lx%2ByH=T%28x%2By%29 ALIGN=MIDDLE  ALT=\"Lx%2ByH=T%28x%2By%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >.\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=Lx%2BHy=Tx%2BTy ALIGN=MIDDLE  ALT=\"Lx%2BHy=Tx%2BTy\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=Lx-Tx=-Hy%2BTy%7D%7D%0D%0A%7B%7B%7B%28L-T%29x=%28-H%2BT%29y ALIGN=MIDDLE  ALT=\"Lx-Tx=-Hy%2BTy%7D%7D%0D%0A%7B%7B%7B%28L-T%29x=%28-H%2BT%29y\"   DISABLED_style= \"max-width:90%; height:auto;\" >,  and since the differences in parentheses would both be negative,  we can multiply left side and right side members by -1 to get,<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28T-L%29x=%28H-T%29y ALIGN=MIDDLE  ALT=\"%28T-L%29x=%28H-T%29y\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x=y%28H-T%29%2F%28T-L%29 ALIGN=MIDDLE  ALT=\"x=y%28H-T%29%2F%28T-L%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "In case x were known but y were the unknown, our solution would be the formula for y,<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=highlight%28y=x%28T-L%29%2F%28H-T%29%29 ALIGN=MIDDLE  ALT=\"highlight%28y=x%28T-L%29%2F%28H-T%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >, THIS is what we want in this bird seed mix problem.\r<BR>\n" );
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document.write( "NOW substitute the known values from given in the problem description.<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=highlight%28y=150%281.3-0.4%29%2F%281.3-.7%29%29 ALIGN=MIDDLE  ALT=\"highlight%28y=150%281.3-0.4%29%2F%281.3-.7%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >, pounds of $1.30/pound sunflower seeds to add.<BR>\n" );
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