Final answer:
The formula for (f/g)(x) is (6x + 5)/(4x + a), which corresponds to option a).
Step-by-step explanation:
To find the formula for (f/g)(x), we divide the function f(x) by the function g(x). The function f(x) is given as 6x + 5 and the function g(x) as 4x + a.
Therefore, the quotient of these functions or the composition (f/g)(x) will be (6x + 5)/(4x + a), which matches the formula in option a).