Final answer:
The correct equation for the cost of the orange juices is A. 5 × 1.25. To calculate Mark's total expense for breakfast, including a $7 tip, you add the cost of the orange juices ($6.25) to the cost of 5 short stacks ($42.50) and the tip, giving a total of $55.75.
Step-by-step explanation:
To calculate the cost of the orange juices that Mark is buying for his family, you need to multiply the quantity of orange juices by the price of each one. The correct equation is A. 5 × 1.25 because Mark is buying 5 orange juices at $1.25 each. This can be written as 5×$1.25=$6.25 for the total cost of the orange juices.
Now, we move on to calculate the cost of the 5 short stacks. The price of one short stack is $8.50, so for 5 short stacks, you would also use multiplication: 5 × $8.50 = $42.50. Including the tip Mark leaves, which is a flat amount and is not affected by the number of items, we add $7 to the total cost. Therefore, the complete equation to calculate Mark's total expense is:
Total expense = (Number of orange juices × Price per orange juice) + (Number of short stacks × Price per short stack) + Tip
Total expense = (5 × $1.25) + (5 × $8.50) + $7
Total expense = $6.25 + $42.50 + $7
Total expense = $55.75
Thus, Mark spends a total of $55.75 for breakfast including tax and tip.