Answer:
f(2)=3(2)=(6)
f(1\2)=3(1\2)=1.5
f(35)=3(35)=105
4.{(2,17),(-7,-4),(-4,3),(0,3)}={(0,3),(-4,3),(-7,-4),(2,17)}
For the 4 ,am not sure of the answer.
