I do not know how the author of that question is using the term "corresponding point". Do you have a definition?
I can guess that since we have $(3,5)\in f(x)$ then $(-2,17)\in 3f(-x+1)+2$
To see that, note that $f(-(-2)+1)=f(3)=5$ BUT still why is that the corresponding point?
Moreover, with that definition, it is hard to guess as to what required part b).
In ordinary set theory, if $(a,b)\in f$ then $(b,a)\in f^{-1}$ Please read the textbook and tell what is meant by corresponding point.