The functions are f(x) = 3x + 4 and g(x) = 5 + x.
\a) (f + g)(x)
\
(Substitute f(x) = 3x + 4 and g(x) = 5 + x)

(Add:
)
b) (f
g)(x)

(Substitute f(x) = 3x + 4 and g(x) = 5 + x)

Apply commutative property of addition:
.

(Subtract:
)
c)

(Substitute f(x) = 3x + 4 and g(x) = 5 + x)
(Using FOIL method)


d)

,
(Substitute f(x) = 3x + 4 and g(x) = 5 + x)
Because x = 5 then 5 + x = 0,
is excluded from the domain of
.