Simple relation diagram graphs question

Draw a relation diagram for the function
f:x→2(3x-1) where x ∈ {1, 2, 3, 4, 5}.

i already know what a relation diagram is. but how do you get the answers to place in the Y colum part? Eg. (the answers) 4,10,16,22,28. how do you do this? can you please explain in detail. i thought i knew how to do it but when i look at the answers i'm always off by 2 or 3 figures. O_o

2(3x - 1)
=2[(3*1) - 1]
=2(3 -1)
=2(2)
=4

=2[(3*2) -1]
=2([6}-1]
=2(5)
=10

2[(3*3)-1]
2[(9)-1]
2(8)
=16

Try the last two on your own. Don't forget to do the stuff inside the parenthesis first.

Sub the 'x' values in for 'x' in your 'r e l a t i o n'

Do the math and the results are corresponding 'y' values.