Answer:
Step-by-step explanation:
Equation representing the relationship between the calories from Protein and fat is,
6p + 9f = 60
1). A). If p = 5 grams  and f = 2 grams,
    Number of calories = (6×5) + (9×2)
                     = 30 + 18
                     = 48 calories
 B). If p = 10.5 grams  and f = 2 grams,
    Number of calories = (6×10.5) + (9×2)
                     = 63 + 18
                     = 81 calories
 C). If p = 8 grams and f = 4 grams
    Number of calories = (6×8) + (9×4)
                     = 48 + 36
                     = 84 calories
(2). If f = 6 grams, then we have to calculate the grams of protein from the given equation.
  4p + (9×6) = 60
  4p + 54 = 60
  4p = 60 - 54
  p = [tex]\frac{6}{4}=1.5[/tex] grams
(3). Combination of 6 grams of fat and 1.5 grams of protein in a snack gives 60 calories of energy.