Question

Each ounce of Food I contains 3 g of carbohydrate and 2 g of protein, and each ounce of Food II contains 5 g of carbohydrate and 3 g of protein. Suppose x ounces of Food I are mixed with y ounces of Food II. The foods are combined to produce a blend that contains exactly 73 g of carbohydrate and 46 g of protein.

a. Explain why there are 3x + 5y g of carbohydrate in the blend and why we must have 3x + 5y = 73. Find a similar equation for protein. Sketch the graphs of both equations.
b. Where do the two graphs in part (a) intersect? Interpret the significance of this point of intersection

Answer 1

The answer is below

Explanation:

a) Food I contains 3 g of carbohydrate and food II 5 g of carbohydrate. x is the number of ounce of food I while y is the number of ounce of food II.

Therefore, the amount of carbohydrate in food 1 is 3x while that of food II is 5y. Since the blend contains exactly 73 g of carbohydrate, the total number of carbohydrate in both food I and food II is 73 g. Hence:

3x + 5y = 73 (1)

Food I contains 2 g of protein and food II 3 g of carbohydrate. Therefore, the amount of protein in food 1 is 2x while that of food II is 3y. Since the blend contains exactly 46 g of protein, the total number of protein in both food I and food II is 46 g. Hence:

2x + 3y = 46 (2)

Using geogebra to Sketch the graphs of both equations.

b) The point of intersection is gotten from the graph, this gives x = 11, y = 8.

The point of intersection shows the amount of food I and food II that give the required amount of protein and carbohydrate.

11 ounce of food I and 8 ounce of food II would produce the required amount of protein and carbohydrate