Desperate need for help!
Maths!
Will award brainliest!

Step-by-step explanation:
fg(x) =
[tex] {(x - 4)}^{2} + 3(x - 4)[/tex]
=
[tex] {x}^{2} + 16 - 8x + 3x - 12[/tex]
=
[tex] {x}^{2} - 5x + 4[/tex]