ANSWER
[tex]{f}^{ - 1} (x) = 7x - 2[/tex]
EXPLANATION
The given function is:
[tex]f(x) = \frac{x + 2}{7} [/tex]
Let
[tex]y = \frac{x + 2}{7} [/tex]
Interchange x and y.
[tex]x= \frac{y + 2}{7} [/tex]
Solve for y by first multiplying through by 7.
[tex]7x = y + 2[/tex]
Add -2 to both sides of the equation.
[tex]7x - 2 = y[/tex]
Or
[tex]y = 7x - 2[/tex]
Hence the inverse function is:
[tex]{f}^{ - 1} (x) = 7x - 2[/tex]