Consider the function g:

{(2, 7), (4, 9), (12, 19), (20, 27), (31, 38)}

what is g (12)?

Another way to ask this question: where the x-value of function g equals 12, what's the y-value?

remember that function notation is like so: f(x), g(x), h(x)... so the number in the parentheses is an x-value from the function.

look through your points and find the one that represents an x-value of 12. (12, 19) is the point, and 19 is your output--so, g(12) = 19.