A=199.(200+1) va B=(199+1).200
A=199.200+199 va B=199.200+200
vi 199.200=199.200và 199<200 nên A<B
Phai giai thich ro rang nha!
Thi to moi cho cau biet chua ha?
A = 199 x 201 =39999
B = 200 x 200 =40000
vậy A > B nên 199 x 201 < 200 x 200
\(A=199\times201=\left(200-1\right)\left(200+1\right)=200^2-1\)
\(B=200\times200=200^2\)
\(\Rightarrow A< B\)
Ta có :
A = 199 x 201 =199 x ( 200 + 1) = 199 x 200 + 199 x 1
B = 200 x 200 =200 x ( 199 + 1) = 200 x 199 + 200 x 1
Ta thấy 199 x 200 = 200 x 199 nhưng 199 x 1 < 200 x 1
Nên A < B
