A= 31 x35 = 31x (33+2)= 31x33+31x2
B = 33 x 33 = 33 x (31 + 2) = 33 x 31 + 33 x 2
Tao thay 31 x 33 + 31 x2 < 33x31 + 33 x 2
Suy ra A<B
tick cho anh cai nao
A = 33*33 = (31+2)*33 = 33*31 + 2*33 (1)
B = 31*35 = 31*(33+2) = 33*31 + 2*31 (2)
2*33 > 2*31 --> (1) > (2) hay A > B