Adding two functions results in h(x) = –x + 9, while multiplying the same functions results in j(x) = –9x. Which statements describe f(x) and g(x), the original functions? Select two options.
A. Both functions must be quadratic.
B. Both functions must have a constant rate of change.
C. Both functions must have a y-intercept of 0.
D. The rate of change of either f(x) or g(x) must be 0.
E. The y-intercepts of f(x) and g(x) must be opposites.