The function is
.
Replace
with y.

Next Switch x for y and y for x.
\

Next solve for y:
\
(Subtract 8 from each side)
(Apply additive inverse property:
)
(Apply additive identity property:
)
(Multiply each side by negative one)
(Apply distributive property:
)
(Product of two same signs is positive)
(Product of two different signs is negative)
(Divide each side by 4)
(Cancel common terms)
(Simplify)
(Divide:
)
The value of
.
Write in function notation, using
to represent the inverse of the function f.

"y" value substitute in above function,
\
.
The inverse function of
is
.