Answer:
A = 2, the number is 3221
Step-by-step explanation:
In order for the number to be divisible by 9, the sum of it's digit has to be divisible by 9.
In our case, [tex]4+A+A+1= 9k[/tex] where k is an integer. the easiest way happens when k=1
[tex]5+2A= 9 \rightarrow 2A=4 \rightarrow A = 2[/tex]
Higher values of k will likely most work (with k=2 you get A to be a non-integer, which can't work since it's the digit of a number, and with higher values of K you're not getting a number in base 10.
