Math help ! input output pleaseeeee

My son needs help and I am horrible at math. I'd like to explain the process so he understands it. Please help us answer these questions.

Does the table represent a function?

1 3
2 4
3 5
4 6

1 3
2 3
3 4
4 4

1 3
1 4
2 5
3 6

5 3
6 4
7 5
8 6

1 3
2 6
3 11
4 18

9 5
9 4
8 3
7 2

also make an input - output table for the function use 0,1,2,3 as the domain

Y=3X+2
Y=6x+1
Y=21-2x
Y=5x
Y=x+4

a function is a relation in which each first input corresponds with exactly one output.

so plot those ordered pair on graphing paper with the x-y coordinate, if you have one x for one distinct y, then it is a function
ordered pair is in the form of (input, output) or (x,y), or (a,b),,,,,,,,,,,
domain is a set of numbers for the input or x elements
while range is a set of number or elements for output or y

I ll put x and y
x....| y
------------
0....|y=3*0+2= 2
1....|y= 3*1+2= 5
so on

so at the end you will have table

x..|y
------
0..|2
1..| 5
so on
repeat the steps for the next y=6x+1