Step 1 :Find the expressions for 2g(a) and 3h(a):
Step 2 :\(2g(a) = 2(2a + 2) = 4a + 4\)
Step 3 :\(3h(a) = 3(a^3 - 3a) = 3a^3 - 9a\)
Step 4 :Subtract 3h(a) from 2g(a):
Step 5 :\((2g - 3h)(a) = (4a + 4) - (3a^3 - 9a) = -3a^3 + 13a + 4\)
Step 6 :Evaluate the expression at a = -3:
Step 7 :\((-3(-3)^3 + 13(-3) + 4) = (-3(27) - 39 + 4) = (-81 - 39 + 4)\)
Step 8 :\boxed{46}\)