The 4th cloumn is equal to (C1 + C2) x C2 &
the 5th row is equal to (C2 x C3)
1st row;
4th number = (2 + 3) x 3 = 5 x 3 = 15
5th number = 3 x 4 = 12
Therefore we can find the missing numbers A & B as;
A = (6 + 7) x 7 = 13 x 7 = 91 &
B = 7 x 8 = 56
Answer is;
A = 91 & B = 56