Evaluate the expression: (3x+1), when x=3

Pls! does anybody know a shortcut for answering these types of questions in the future?

Check all that apply. f is a function. f is a one-to-one function. c is a function. c is a one-to-one function.

What is the domain of the given function? {(3,-2), (6, 1), (-1, 4), (5,9), (-4, 0); o {x | x= -4,-1, 3, 5, 6} o {yl y = -2,0, 1,4,9} o {x|x = -4,-2, -1,0, 1, 3, 4, 5, 6, 9} o y y = 4,-2, -1, 0, 1, 3, 4, 5, 6, 9}