Question 393247
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Hi
Let x and y represent  the cost/cup for coffee and tea respectively
 6x + 7y = $5.90
18x + 5y = $9.70

-18x -21y = 5.90*-3
18x  + 5y = 9.70
      -16y = -8
         y = .50, cost/cup for tea
6x + 7y = 5.90
6x + 3.50 = 5.90
       6x = 2.40
        x = .40, cost/cup for coffee
total bill for 7 cups of coffee and 6 cups of tea?
  7*.40 + 6*.50 = $5.80