21x22 +32x78+32
=462 + 2496 +32
=2990
nếu vậy thì
21 x 32 + 32 x 78 +32
=(78 + 21 ) x32 +32
= 3168 + 32
= 3200
21x22+32x78+32
=21x22+32(78+1)
=462+2528
=2990
k mik nha
21 x 22 + 32 x 78 + 32
= 21 x 22 + 32 x 78 + 32 x 1
= 21 x 22 + 32 x ( 78 + 1 )
= 462 + 32 x 79
= 462 + 2528 = 2990