In a bread recipe, the amount of flour used must be a non-negative quantity. Let's evaluate the options:
- −3: Negative quantity, cannot have negative cups of flour.
- Square root of 3: Approximately 1.732, which is a positive quantity. This could be used in a recipe.
- 4/7: Approximately 0.571, which is positive and could be used in a recipe.
- 2 3/4: This is 2.75, a positive quantity that can definitely be used in a recipe.
The valid numbers for specifying cups of flour in a bread recipe are:
- Square root of 3
- 4/7
- 2 3/4
So, any of those positive quantities could be used for flour in a recipe, while −3 is not valid.