The function is
.
Replace
with y.

Next switch x for y and y for x.
\
.
Next solve for y:
\
(Multiply each side by negative one)
(Apply distributive property:
)
(Product of two different signs is negative)
(Product of two same signs is positive)
(Add 2 to each side)
(Apply commutative property of addition:
)
(Apply additive inverse property:
)
(Apply additive identity property:
)
(Divide each side by 7)
(Cancel common terms)
(Simplify)
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
.