Final answer:
Options C and D (-5x + 4 and 2x - 1) are functions of x because they can be written in the form y = mx + b, where each x-value has exactly one corresponding y-value.
Step-by-step explanation:
The question is asking which relation is a function of x. A function of x is defined by the rule that for each value of x, there is only one corresponding value of y. Reviewing the options provided:
- Option A: {(1, 2), (7, 6), (3, 2), (1, 0), (5, 6)} is not a function because the x-value of 1 is paired with two different y-values (2 and 0).
- Option B: x = 3y2 - 7 is not a function in terms of x, since for a single value of x, there could be two different y values.
- Options C and D: -5x + 4 and 2x - 1 are both examples of equations that represent functions because they can be rewritten in the standard function form y = mx + b, where m and b are constants.
Therefore, both options C and D represent functions of x.