Answer:
f(3 + 4)
Explanation:
Since they are exponents...,
If f(x) = a^x....then substitute as given,
; f(3) = a^3
; f(4) = a^4
Hence as the question states
f(3).f(4) = a^3 × a^4
; If the values are of the same base...,
then we add the exponents if the question is of multiplication
; a^3+4....in which our new x = (3 + 4)
;Which is the one that we substitute onto the value of x in f(x)
Hence answer... f(3 + 4)