Answer:
37.57 + 1.95x
Explanation:
The cost of the shoes is a constant, and we don't know how many socks she bought, but we know that for every pair of socks she bought, they cost would be 1.95. Since we haven't been given the total cost of the purchase, meaning how much the total was, this will be an expression. We will multiply an x against the amount (1.95), which will calculate the price for how many socks were purchased. This means the answer will be 37.57 + 1.95x.
I will clarify a little bit more on why the other answers are incorrect. The first option is 37.57x + 1.95. This is incorrect because the question is not asking how many shoes were bought, but it is questioning how many socks were bought. Option number two states 37.57x + 1.95x. This means that the number of socks and shoes are both unknown, and the question does not state that. Also, another point to make would be that we could also add these variables together, and we do not want that. Option number three states 37.57 + 1.95 + x. X cannot be a separate variable, because by stating that, it means that there would be one more object that was bought that is unknown. I hope this helps you understand my explanation a bit more.
Have a great day, and best of luck for your math problem!