Answer: 5
Step-by-step explanation:
We know that when a liner function is represented by a graph i.e. by a line, then its initial value is represented by the y intercept of the line.
In the given graph , we can see that the y-intercept of the function is point (0,5).
The y -intercept of the function : 
Then , the initial value of the function will also be 5.
Hence, the initial value of the function represented by this graph=5