Answer:
12 - 2x.
Step-by-step explanation:
f(x) - g(x) = x^2 + 2x - 3
f(x) = x^2 + 9 so:
x^2 + 9 - g)x) = x^2 + 2x - 3
x^2 + 9 - (x^2 + 2x - 3) = g(x)
g(x) = x^2 + 9 - x^2 - 2x + 3
g(x) = 9 + 3 - 2x
g(x) = 12 - 2x.
