Let x represent first number in pair and y represent second number. We can see that x numbers are increasing by 1 on each next pair. y numbers are square of 0,2,4,6 and 8
Knowing all of that let "n" represent the position of the pair starting from 0!
than we can write that the rule is:
(n,(2n)^2)

A linear function has 1 as the highest power of the variable.
A. f(x) = 2 - 7x
here, the highest power of the variable x is 1.
Hence it is a LINEAR function.
___________
B. f(x) = 2 + x + x^2
here, the highest power of the variable x is 2.
Hence it is NOT a linear function.
_______________

here, the highest power of the variable x is 1/2.
Hence it is NOT a linear function.
________________