Final answer:
All of the given relations (A. y = 2x, B. y = 5x, C. y = -5x + 3, D. y = -10x + 15) are functions because they all represent linear equations, and each x-value corresponds to exactly one y-value.
Step-by-step explanation:
The student has asked which of the given relations is a function. A function is a special type of relation where every input (x-value) is associated with exactly one output (y-value). Looking at the options given:
- A. y = 2x
- B. y = 5x
- C. y = -5x + 3
- D. y = -10x + 15
All these relations are in the form of y = mx + b, which is the standard form for a linear equation. Since each x-value produces a unique y-value, all of these relations are indeed functions.