Answer: 16. f(1)=-2
17. f(-3)=1
18. x=0
19. x=-1 and x=1
Step-by-step explanation:
16. f(1)=-2
18. f(x)=-3
x=0 ==> f(0)=-3
19. f(x)=-2
x=-1 and x=1 ==> f(-1)=-2, f(1)=-2
