Find all values that are NOT in the domains for the following rational functions.
a. f(x) = 5x+4/8x+16
b. g(x) = 2x-1/x^2-49
c. p(x) = x^2+2x+7/2x^2-5x+3
d. q(x) = 3x/5x^3 + 3x^2-2x