Final answer:
it is impossible to solve for A. The question provided is incomplete and lacks the necessary information to reach a solution.
Step-by-step explanation:
To solve the proportion without including the variable, we would have to be given the complete proportion to find its solution.
However, since the question is incomplete and does not provide the proportion or equation in question, we can't directly solve it.
If we assume that you've provided part of an equation where 1 is set to equal 5A, and another part where 13 equals -2A, we could try to find a connection between the numbers provided in your question, but we can't provide an exact answer without the full proportional equation.
Nonetheless, if in a different scenario, we were given a proportion, for example, (A/1) = (-2A/13), we could cross-multiply and solve for A, but this is not what has been asked here.