Since you can't subtract different variables,you would need to just multiply.So in C, the 3 and 2 make 6,add the g making 6g. 3 and 6 make 18 add the h and no variable cancel each other out.
In E,the negatives in 2 and -3 cancel out making 6g and the 9 times -2 makes -18,add the h.