a) =49x62+62x51
=62x(49+51)
=62x100
=6200
b)còn câu b =3724 nha
a , 49 x ( 37 + 25 ) + 62 x ( 121 - 70 )
= 49 x 62 + 62 x 51
= 62 ( 49 + 51 )
= 62 x 100
= 6200
b , 25 x 38 + 146 x 19
= 25 x 38 + 73 x 2 x 19
= 25 x 38 + 73 x 38
= 38 ( 25 + 73 )
= 38 x 98
= 3724