Ta có:
A = 42 x 53 - 41
A = ( 41 + 1 ) x 53 - 41
A= 41 x 53 + 41 - 41
A = 41 x 53 < 41 x 53 + 30
\(\Rightarrow A< B\)
Vậy \(A< B\)
Ta có:
A = 42 x 53 - 41
A = ( 41 +1 ) x 53 - 41
A= 41 x 53 + 53 - 41
A = 41 x 53 + 12 < 41 x 54 + 30
=> A < B
Vậy A < B
( bài kia mk nhầm sorry nha )