Easy
ABB+CBB = DDD
A=2, B=3, C=4, D=6
A=1, B=4, C=7, D=8
A=2, B=4, C=6, D=8
A=1, B=3, C=5, D=6
A=3, B=4, C=5, D=8
A=1, B=2, C=3, D=4
ABC+CDC = DC04
A=9, B=8, C=7, D=1
AB*A = 8B8
A=9, B=2
AB-BA = 27
RECHECK - DOES IT WORK?
ABCD*9 = DCBA
A=1, B=0, C=8, D=9
d+cd+bcd+abcd=2008
A=1, B=4, C=6, D=7
A+AB+ABC+ABCD=1879
A=1, B=6, C=9, D=3