Final answer:
In order to find the cost of one pound of butter, we can set up an equation using the given information and solve for x. The cost of one pound of butter is $1.75.
Step-by-step explanation:
Let the cost of one pound of butter be x dollars.
Given that a pound of peanuts costs four times as much as a pound of butter:
Cost of one pound of peanuts = 4x dollars
In the recipe, 12 pounds of butter and 10 pounds of peanuts are required. Therefore, the total cost of the batch of peanut butter can be calculated as:
Total cost = (12 * x) + (10 * 4x) = 12x + 40x = 52x dollars
Given that the total cost of the batch of peanut butter is $91, we can set up the following equation:
52x = 91
Dividing both sides of the equation by 52, we get:
x = 91 / 52 = 1.75 dollars
Therefore, one pound of butter costs $1.75.