pre calc question find f(x)?

Question

I got both wrong im not sure what to do.

Given f(x)= x/ x-1 g(x)= 2x-4/x

find a) (gog) (0)

and b) (fog)(-3)

for a) i got 2 and b) i got -5/6 but they are marked as wrong

Answer 1

g of g of 0 is

2(g(0)) - 4/(g(0))

g of 0 is 2(0) - 4/0.

4/0 is undefined, so you have 2 - undefined.

2 - undefined is undefined.

g of g of 0 is undefined.

f of g of 3 is

g(3)/(g(3)-1)

g of 3 is 2(3) - 4/3 = 6 - 4/3 = 14/3.

so f of g of 3 = (14/3) / (14/3)-1

= (14/3) / (11/3)

= (14/3) * (3/11)

= 42 / 33

= 14 / 11