Sebastian wants to leave a 34% tip, and the dinner costs d dollars. To find the total cost including the tip, we need to add 34% of d to the original cost d.

The tip is calculated as: $0.34 \times d$ Thus, the total cost (dinner + tip) is: $d + 0.34d = 1.34d$

Now let's match this with the given answer options:

• 1.034d (Incorrect: this implies a 3.4% tip, not 34%)
• d + 0.34d (Correct: this represents the dinner plus 34% of the cost)
• d + 0.34 (Incorrect: this adds a flat $0.34, not 34% of the cost)
• 1 + 0.34 (Incorrect: this isn't relevant to the cost and tip)

So, the correct answer is: d + 0.34d.

Would you like further explanation on any part of this? Here are 5 related questions to think about:

1. How would the expression change if the tip percentage was 15% instead of 34%?
2. Can you convert 34% into a fraction, and would the expression change using the fraction form?
3. How can you calculate the tip for a dinner that costs $45?
4. What is the final bill if d is $100 with a 34% tip?
5. How does the formula change if taxes are included on top of the tip?

Tip: Percentages are often used in pricing problems; converting them into decimals (like 34% = 0.34) makes the calculation straightforward.