Let's assume the number of servings of roast beef is x, and the number of servings of mashed potatoes is y.
Hence, we have the following equations:
25x + 2y = 29 (Equation 1, for protein)
11x + 25y = 61 (Equation 2, for calcium)
Multiplying Equation 1 by 11 and Equation 2 by 25 to eliminate the respective 'x' terms:
275x + 22y = 319 (Equation 3, after multiplying Equation 1 by 11)
275x + 625y = 1525 (Equation 4, after multiplying Equation 2 by 25)
Subtracting Equation 3 from Equation 4, we get:
625y - 22y = 1525 - 319
603y = 1206
y = 1206/603
y = 2
Substituting the value of y into Equation 1, we have:
25x + 2(2) = 29
25x + 4 = 29
25x = 29 - 4
25x = 25
x = 25/25
x = 1
Therefore, 1 serving of roast beef and 2 servings of mashed potatoes are needed to supply exactly 29 g of protein and 61 g of calcium.
Roast beef has 25 g of protein and 11 g of calcium per serving. A serving of mashed potatoes has 2 g of protein and 25 g of calcium. How many servings of each are needed to supply exactly 29 g of protein and 61 g of calcium?
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