Answer:

Explanation:
Clearly from the graph we could see that it passes through two points (0,25) and (20,30) and also as the graph is linear so with the help of these two points we can find the relation between f(x) and x.
We know that the equation of a line passing through two points (a,b) and (c,d) is given by:

Here we have:
y=f(x) , (a,b)=(0,25) and (c,d)=(20,30).
Hence the equation of this graph is given as:

Hence,
