Question

LOOK, 25 POINTS Y'ALL

Answer 1

To start, ABCD(D)=DCBA means that D×A=D because they're all single digit numbers and since nothing carries over to make DCBA a 5 digit number A must be 1. If A is 1 for ABCD(D)=DCBA that would mean D^2 is a number ending in 1 so the only possibility for D is 9. Since D is 9, D×B has to be less than 10 because we know nothing carries over to the D×A (9×1) so B has to be 0. So far we have 10*9(9)=9*01 and since D×D (9×9) is 81 we need a number divisible by 9 that ends with 2 to add to the 8 digit which the only possibility is 72 from 8×9. SO A=1, B=0, C=8, D=9
1089(9)=9801