We are given that f(x) = x^2 - 4 and g(x) = x + 3. We have to solve for x given thatÂ f(g(x)) = 0.

f(g(x)) = 0

=> f( x +3) = 0

=> (x +3)^2 - 4 = 0

=> (x + 3 - 2)(x + 3 + 2) = 0

(x + 3 - 2) = 0

=> x = -1

(x + 3 + 2) = 0

=> x = -5

**The solutions for x are x = -1 and x = -5**