Final answer:
The question is about the properties of a mathematical function, specifically with respect to values, slope, and symmetry related to even and odd functions. Although the question contains unclear parts, we can determine that a function with a positive value and a positive, decreasing slope with increasing x could be represented by y = x^2.
Step-by-step explanation:
The question at hand is a mathematics problem dealing with the properties of functions. Specifically, it appears to involve understanding the characteristics of a function such as its slope, the positive or negative values it can take, and the kind of transformations that reflect symmetry for even and odd functions. Unfortunately, the question seems to include unclear and potentially misleading information, which may be considered a typo or an irrelevant part. However, if we focus on the cleaner part of this scenario presented in an example (75.), where we understand that a function defined at x = 3 has a positive value, with a positive slope that is decreasing in magnitude with increasing x, we could infer that option b, y = x2, is a function that increases and has a positive slope that decreases as x increases.