Only two points are given. An infinite number of functions can be written that will have graphs going through those two points. We have to assume the only one you're interested in is the linear function.
You can use the 2-point form of the equation for a line to find the function, then use that to fill in the table.

Using this rule Output = Input -2, we can fill in the function table.
There would be 12 different digits.
The number of this always corresponds to the number in the base. Consider our current system which is base 10. We have 10 numbers we can use for digits (0-9). So a base 12 system would have to have 12.
3 x 2 x 2 x 2 x 2 / 2 x 2 x 2
48 / 2 x 4
[48 can be simplified to 24 x 2 and 4 can be simplified to 2 x 2]
24 x 2 / 2 x 2 x 2
[24 can be simplified to 12 x 2]
12 x 2 x 2 / 2 x 2 x 2
[12 can be simplified to 6 x 2]
6 x 2 x 2 x 2 / 2 x 2 x 2
[6 can be simplified to 3 x 2]
3 x 2 x 2 x 2 x 2 / 2 x 2 x 2
Answer: the answer to this question is 17
Step-by-step explanation: