Final answer:
To calculate the change c(x) from a $20 bill when buying x pounds of pears at $0.79/lb, first calculate the total cost (x * $0.79) and then subtract it from $20 to get the change (c(x) = $20 - x * $0.79).
Step-by-step explanation:
Calculating Change from a $20 Bill
You are asking how to calculate the amount of change c(x) you would receive from a $20 bill if you buy x pounds of pears at $0.79 per pound. To solve this problem, we need to follow a simple two-step process:
- Calculate the total cost of the pears by multiplying the number of pounds x by the cost per pound ($0.79). This is represented by the equation: total cost = x * $0.79.
- Determine the change from the $20 bill by subtracting the total cost of the pears from $20. This is represented by the equation: change c(x) = $20 - (x * $0.79).
Using the examples provided as a reference, let's consider analogous computations:
- For apples, you would calculate the total cost as: 10 apples * $0.50 = $5.00.
- For bananas: 12 bananas * $0.20 = $2.40.
- For grapes: 2 bunches * $0.65 = $1.30.
- For raspberries: 1 pint * $2.00 = $2.00.
These show how to multiply the quantity by unit price to find the total cost, as we have done with the pears in the original question.