PLEASE HELP
Determine wether the table of values in each part represents a linear function. For those that represent linear functions, write the function. For those that do not, explain why not.

Part A
X
3
4
5
6
f(x)
14
18
23
29

Part B
X
0
1
2
3
f(x)
2
-1
-4
-7

Part C
X
1
2
3
4
f(x)
11
16
21
26