Final Answer:
To find the total plus tip in one step, Annabelle should multiply the cost of the meal by 1.23 (Option A).
Step-by-step explanation:
To calculate the total plus tip, you need to add the cost of the meal to the tip amount. Since Annabelle wants to leave a tip of 23%, the total cost including the tip is found by multiplying the cost of the meal by 1 plus the tip percentage in decimal form (1 + 0.23). This simplifies to 1.23, so multiplying the cost of the meal by 1.23 gives the total plus tip amount in one step (Option A).
Mathematically, the expression for the total plus tip can be represented as T = C * (1 + r), where T is the total plus tip, C is the cost of the meal, and r is the tip rate in decimal form. In this scenario, r is 0.23 for a 23% tip. Therefore, the expression becomes T = C * 1.23, which is the same as multiplying the cost of the meal by 1.23 to directly obtain the total plus tip.
In conclusion, by choosing the multiplier 1.23, Annabelle can efficiently calculate the total plus tip in one step. This approach simplifies the calculation and is a practical method for determining the total cost when leaving a specified percentage tip on a meal.