Answer
$a$
Work Step by Step
RECALL:
In an exponential function, $\dfrac{f(x+1)}{f(x)} = a$
Thus, the missing expression in the given statement is $a$.
You can help us out by revising, improving and updating this answer.
Update this answerAfter you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.