document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1160612>Question 1160612</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A type of pasta is made of a blend of quinoa and corn. The pasta company is not disclosing the percentage<BR>\n" );
document.write( "of each ingredient in the blend but we know that the quinoa in the blend contains 14.5% protein, and the<BR>\n" );
document.write( "corn in the blend contains 2.5% protein. Overall, each 60 gram serving of pasta contains 4 grams of<BR>\n" );
document.write( "protein. Model a systems of equations for this problem and solve the system to find how much quinoa and<BR>\n" );
document.write( "how much corn is in one serving of the pasta?  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #783966 by </B><A HREF=/tutors/aboutme.mpl?userid=greenestamps><B>greenestamps(13206)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=greenestamps><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=greenestamps><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=783966\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <br><BR>\n" );
document.write( "Let x = grams of quinoa<BR>\n" );
document.write( "Let y = grams of corn<br><BR>\n" );
document.write( "Then 0.145x = grams of protein in the quinoa<BR>\n" );
document.write( "and 0.025y = grams of protein in the corn<br><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x%2By+=+60 ALIGN=MIDDLE  ALT=\"x%2By+=+60\"   DISABLED_style= \"max-width:90%; height:auto;\" >  the sample is 60 grams<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=0.145x%2B0.025y+=+4 ALIGN=MIDDLE  ALT=\"0.145x%2B0.025y+=+4\"   DISABLED_style= \"max-width:90%; height:auto;\" >  the amount of protein is 4 grams<br><BR>\n" );
document.write( "Usually when a system of linear equations has both equations in the form ax+by=c, I would use elimination.  But with the ugly coefficients in the second equation, I choose to use substitution.<br><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=y+=+60-x ALIGN=MIDDLE  ALT=\"y+=+60-x\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=0.145x%2B0.025%2860-x%29+=+4 ALIGN=MIDDLE  ALT=\"0.145x%2B0.025%2860-x%29+=+4\"   DISABLED_style= \"max-width:90%; height:auto;\" ><br><BR>\n" );
document.write( "I'll let you finish from there.<br><BR>\n" );
document.write( "Note that the last equation I show in my work is what would be my starting equation, if the instructions had not said to use a system of equations.  Nearly always, solving a problem using a single variable and a single equation is easier and faster than solving a pair of equations in two variables.<br><BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );