If the five digit number aa448 is divisible by 9, what digit does a represent?

a=1

Step-by-step explanation:

If the number is divisible by 9 the sum of its digits is divisible by 9 as well.

The numbers 18, 27, 36 are divisible by 9. Check each of them.

a+a+4+4+8=2a+16=18

2a=2

a=1

2a+16=27

2a=11

a=5.5 - it is not the digit. So is not the solution.

2a+16=36

2a=20

a=10 is not a digit, so isn't a solution

any bigger number divisible by 9 (45,54,63 ...) wil not give the digit.

So there is only 1 solution a=1