Question

Given: F = {(0, 1), (2, 4), (4, 6), (6, 8)} and G = {(2, 5), (4, 7), (5, 8), (6, 9), (7, 5)}

(F - G) (6) =

Answer 1

Thanks for the explanation mate that was helpful^^

Answer 2

The ordered pair (6, 8) in the definition of F tells you F(6) = 8.
The ordered pair (6, 9) in the definition of G tells you G(6) = 9.

(F-G)(6) = F(6) - G(6) = 8 - 9 = -1