Final answer:
The restaurant used 23,336.1 ounces of cream last year.
Step-by-step explanation:
To find out how much cream the restaurant used last year, we need to calculate 10% more than the amount used this year. First, we can calculate the 10% decrease of 25,929 ounces by multiplying it by 0.10, which gives us 2,592.9 ounces. Then, to find the amount used last year, we subtract this decrease from this year's usage:
25,929 ounces - 2,592.9 ounces = 23,336.1 ounces.