Answer:
Table P represents a function
Step-by-step explanation:
* Lets explain the meaning of the function
- A function is a relation between a set of inputs and a set of outputs
 in condition of each input has exactly one output
- Ex:
# The relation {(1 , 2) , (-4 , 5) , (-1 , 5)} is a function because each x in the
  order pair has only one value of y
# The relation {(1 , 2) , (1 , 5) , (3 , 7)} is not a function because there is x
  in the order pairs has two values of y (x = 1 has y = 2 and y = 5)
* Lets solve the problem
# Table P :
- In put   : 8  ,  1  ,  5
- Out put : 3 Â , Â 7 Â , 4
∵ Each input has only one output
∴ Table P represents a function
# Table Q :
- Input   : 9  ,  9  ,  4
- Out put : 3 Â , Â 5 Â , Â 2
∵ The input 9 has two outputs 5 and 2
∴ Table Q doesn't represent a function
# Table R :
- In put   : 7  ,  8  ,  7
- Out put : 2 Â , Â 6 Â , Â 3
∵ The input 7 has two outputs 2 and 3
∴ Table R doesn't represent a function
# Table S :
- In put   :  1  ,  1  ,  9
- Out put : Â 7 , Â 5 Â , Â 2
∵ The input 1 has two outputs 7 and 5
∴ Table S doesn't represent a function
* Table P represents a function
