Find an expression for f⁻¹(x) for each of the following functions.

a) f(x) = 2x + 3, x ∈ R

b) f(x) = x² − 2, x ∈ R x ≥ 0

c) f(x) = 1 − 4x, x ∈ R

d) f(x) = x − 3/2, x ∈ R

e) f(x) = 1/x, x ∈ R, x ≠ 0

f) f(x) = 2(x − 1), x ∈ R