Question 892194
Price is like a concentration in the unit of dollars per piece. You can use cents per piece in your example if you want.


L = 10 cents per piece (caramel)
H = 50 center per piece (chocolate)
v = unknown, pieces of chocolate
u = unknown, pieces of caramel
M = 20 pieces
T = 6.80/20 dollars per piece, the effective price of per purchase.  This price is 0.32 dollars per piece, or <b>32 CENTS per PIECE</b>.


These two equations are the system to solve for u and v.  You can use the equation for form ONE equation in just the unknown, v.


{{{highlight_green((Lu+Hv)/M=T)}}} and {{{highlight_green(u+v=M)}}}.


A complete lesson is here:  <a href="http://www.algebra.com/tutors/mixture-price-two-part-both-parts-unknown.lesson?content_action=show_dev">Mixture: Two-Part, price or cost, both material amounts unknown - http://www.algebra.com/tutors/mixture-price-two-part-both-parts-unknown.lesson?content_action=show_dev</a>