
Actually Welcome to the Concept of the Functions.
Let's first find the g(-1),
so we get as
3(-1)^2 +5(-1)-6
=> 3 -5-6
=> -8
now since g(-1) =-8
let's find f(g(-1)) that is f(-8)
f(-8) = 4(-8) + 14
=> f(g(-1)) = -32+14
=> f(g(-1)) = -18
-18 is the answer.