Question 1042498
Assign some variables to anything not known.


x    pounds of the expensive coffee, the gourmet coffee
c    pounds of the cheap coffee, which is the regular coffee
m    pounds of the mixture


You find from the description that x=10.    Account for pounds of coffee and for price of the mixture to be made.  c and m seem to be the unknown quantities.


QUANTITY ACCOUNT:  {{{c+10=m}}}


PRICE ACCOUNT:  {{{(9c+14*10)/m=12}}}



Those two equations together are the system of equations in variables c and m.  Solve this system of equations.  


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