Answer: c ≤ 4.5 or c ≥ 12
Step-by-step explanation:
Let c denote the number of ounces of clay that Elisa uses to make one vase of either size.
Given statements are: To make a small vase, Elisa uses no more than 4.5 ounces of clay.
The words "no more than" implies "less than or equals to"
hence, for small vase c must be less than or equals to 4.5 oz, which gives
...(1)
To make a large vase, she uses at least 12 ounces of clay.
The word "at least" means "more than or equals to"
hence, for large vase c must be more than or equals to 12 oz, which gives
...(2)
Combining (1) and (2), we get
c ≤ 4.5 or c ≥ 12