Which of these relations are functions?𝑦 = 5𝑦 = 2𝑥 − 5𝑥 = −22𝑦 = 𝑥 − 4

A function is a relation in which each input has exactly one output. In other words, for every x-value there is exactly one y-value.

1. 𝑦 = 5: This is a function. No matter what x-value you input, the output will always be 5.

2. 𝑦 = 2𝑥 − 5: This is a function. For every x-value, there is exactly one y-value.

3. 𝑥 = −22: This is not a function. This is because no matter what y-value you input, the output will always be -22. In other words, there are multiple y-values for the same x-value, which violates the definition of a function.

4. 2𝑦 = 𝑥 − 4: This is a function. If you rearrange this equation to solve for y (𝑦 = 0.5𝑥 - 2), you can see that for every x-value, there is exactly one y-value.