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put this solution on YOUR website! A merchant mixed 12 lb of a cinnamon tea with 5 lb of spice tea. The 17-pound mixture cost $28. 
A second mixture included 14 lb of the cinnamon tea and 8 lb of the spice tea. The 22-pound mixture cost $37. 
Find the cost per pound of the cinnamon tea and of the spice tea.
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    12x + 5y = 28   dollars     (1)
    14x + 8y = 37   dollars     (2)
Multiply equation (1) by 8 (both sides).
Multiply equation (2) by 5 (both sides).  You will get
    96x + 40y = 28*8            (3)
    70x + 40y = 37*5            (4)
From equation (3), subtract equation (4).  You will get
    26x       = 28*8 - 37*5 = 39
      x                     = 39/26 = 
 = 1.50  dollars.
To find y, substitute the found value x= 1.50 into equation (1). You will get
    12*1.50 + 5y = 28
    18      + 5y = 28
              5y = 28-18 = 10
               y         = 10/2 = 5.
ANSWER.  Cinamon tea price is $1.50 per pound.  The spice tea price is $2.00 dollars per pound.
Solved.
The method I used in the solution, is called the ELIMINATION method.