C & D Answer Choices Are The Same, Your Answer Is 42c-19
[tex]f(x) = \: all \: x \: in \: (7x + 9)[/tex]
[tex]f(x) = 7x + 9[/tex]
[tex]f(6c - 4) = 7x + 9[/tex]
*Distributive Property
[tex]f(6c - 4) = 7(6c - 4) + 9[/tex]
[tex]f(6c - 4) = 42c - 28 + 9[/tex]
[tex]f(6c - 4) = 42c - 19[/tex]
