Our first condition:
B × 6 gives unit digit as B
Let's put B = 2
2 × 6 = 12
Here unit digit as B which is 2 and 1 as carry.
A × 6 = BB or
carry + A × 6 = BB
Put A = 7 then
1 + 7 × 6 = 43
So the values of A and B are not correct.
Put value B = 4
4 × 6 = 24
Here unit digit as B which is 4 and 2 as carry
Now, our next condition
6 × A + Carry = BB
If put the value of A as 7 then
6 × 7 + 2 = 44
Yes it satisfies the above equation.
A = 7 , B = 4.