Answer:
We get 
Step-by-step explanation:
We are given:

We need to find (f-g)(x) (assuming there is x in the bracket, i.e. (f - g) () should be (f-g)(x))
We would simply subtract f(x) and g(x)

So, We get 
Answer: For 10 sessions, the cost of the two plans the same.
Step-by-step explanation:
Let x= Number of sessions.
Given: Christian’s Gym charges a one-time fee of $50 plus $30 per session for a personal trainer.
Total charge for x sessions = 50+30x
Nicole's fitness center charges a yearly fee of $250 plus $10 for each session with a trainer.
Total charge for x sessions = 250+10x
When both plan charges the same, then

i.e. For 10 sessions, the cost of the two plans the same.
Answer:
-3x-y=10
Step-by-step explanation:
y+4=-3(x+2)
y+4=-3x-6
y=-3x-6-4
y=-3x-10
-3x-y=10
The last side would be 10