Answer: the amount by which her lunch account would have been impacted is $45
Step-by-step explanation:
Each day Valerie charges her lunch account for her lunch. If the cost of lunch is $3 then, it means that Valerie charges the lunch account with $3 daily. It means that in x days, she would have charged her lunch account with 3×x = $3x
If she charged her account for a period of 15 days, it means that x = 15. Therefore, the amount by which her lunch account would have been impacted is 3×15 = $45
Answer: Second option.
Step-by-step explanation:
It is important to remember the Distributive Property in order to solve this exercise.
The Distributive property states that:

In this case you have the following expression provided in the exercise:

Then, in order to write this expression in another way, you can apply the Distributive property. Multiply each number inside the parentheses by "t".
Applying this procedure, you get:

Notice that this expression matches with the one shown in the the second option.