b) 1994 ×867 + 1995 × 133
Giải thích
a) 1994 ×867 + 1995 × 133
= 1994 × 867 + ( 1994 + 1 ) × 133
= 1994 × 867 + 1994 × 133 + 133
= 1994 × ( 867 + 133) + 133
= 1994 × 1000 + 133
= 1994000 + 133
= 1994133
a) 1994 ×867 + 1995 × 133
= 1994 × 867 + ( 1994 + 1 ) × 133
= 1994 × 867 + 1994 × 133 + 133
= 1994 × ( 867 + 133) + 133
= 1994 × 1000 + 133
= 1994000 + 133
= 1994133