Function Sets 55D1Fc

1. **State the problem:** We need to determine which of the given sets of ordered pairs represents a function. 2. **Recall the definition of a function:** A set of ordered pairs is a function if every input (first element of each pair) corresponds to exactly one output (second element). 3. **Analyze each set:** - Set A: $\{(9,0), (9,1), (9,2), (9,3)\}$ - The input $9$ maps to multiple outputs $0, 1, 2, 3$. - This violates the function rule. - Set B: $\{(-1,0), (-2,0), (2,0), (1,0)\}$ - Inputs are $-1, -2, 2, 1$ each mapping to $0$. - Each input has exactly one output. - This is a function. - Set C: $\{(-2,0), (3,1), (3,2), (1,3)\}$ - Input $3$ maps to both $1$ and $2$. - Violates the function rule. - Set D: $\{(9,5), (9,5), (9,5), (9,5)\}$ - Input $9$ maps to $5$ consistently. - This is a function. 4. **Conclusion:** Sets B and D are functions. 5. **Final answer:** The sets that are functions are B and D.