386 x 156 + 386 - 57 x 386
= 386 x ( 156 + 1 - 57 )
=386 x 100
= 38600
= 386 x ( 156 - 57 + 1 )
= 368 x 100
= 368000
hok tốt
386 x 156 + 386 - 57 x 386
= 386 x (156 + 1 - 57 )
= 386 x 100
= 38600
\(386\times156+386-57\times386\)
\(=386\times157-57\times386\)
\(=386\times\left(157-57\right)\)
\(=386\times100\)
\(=38600\)