Answer:
f⁻¹(1/5) = 2
Explanation:
If f(x) = (2x -3)/5
To find inverse of f(x), make x the subject.
[tex]f(x) = \dfrac{2x - 3}{5}[/tex]
[tex]5 f(x) = 2x - 3[/tex]
[tex]2x = 5 f(x) + 3[/tex]
[tex]x = \dfrac{5 f(x) + 3}{2}[/tex]
Then,
[tex]f^{-1}(x) = \dfrac{5x+3}{2}[/tex]
To find f⁻¹(1/5), simplify insert [x = 1/5 or 0.2]
[tex]f^{-1}(0.2) = \dfrac{5(0.2)+3}{2}[/tex]
which yields
[tex]f^{-1}(0.2) = 2[/tex]
