Translation:She used to pay when we went to the restaurant.
my answers to the listening exercise were:
elle payait quand nous allions aux restaurants
ells payaient quand nous allions au restaurant.
Both should be correct, either per the pronunciations or per logical understanding.
So should that be using "ells payaient ..."
There is however no option to report.
As an adjective, always use 'used to' ie 'I am used to a certain standard of living'.
As a verb, the base is 'use to' but, since this is always referring to the past, use 'used to' unless you are using 'did' or 'didn't' with it.
'Did you use to go swimming?' 'Yes, I used to go swimming.' 'Your father used to go with you, didn't he?' 'No, he didn't use to go with me.'