Answer:
Part 1) The inverse function is 
Part 2) 25.75 weeks
Step-by-step explanation:
Let
x ---->the number of weeks in the course
f(x) ---> the number of assignments he has completed
we have

Part 1) Find the inverse
Let
y=f(x)

Exchange the variables (x for y and y for x)

Isolate the variable y

Let

so

Part 2) we have

where
---->the number of weeks in the course
x ---> the number of assignments he has completed
For x=50
substitute in the inverse function

Note: Juliana don't need to use the inverse function. you can just use the function you have where f(x)=50 assignments and solve for x to get the amount of weeks.
so
