Answer:
f(x) + g(x) = x² – 3x + 24, with some assumptions on what is meant in the question.
Explanation:
f(x) = x² – 3x 18 [I'll assume this is meant to be x²-3x +18]
g(x) = r = 6 [I don't understand this. I'll assume simply that g(x) = 6]
f(x) + g(x) = x² – 3x + 18 + 6
f(x) + g(x) = x² – 3x + 24