Find the inverse of the one-to-one function f(x) = (6x - 8) / 7.
a) f⁻¹(x) = 7x - 8/6
b) f⁻¹(x) = 7x - 8
c) f⁻¹(x) = 6x - 7/8
d) f⁻¹(x) = 7/6x + 8/6