a) 32 x 53 -21 / 53 x 31 + 32
= (31+1)x 53 -21/ 53 x 31+32
=31x53 + 53 x 1/ 53 x31 +32
=31 x 53 +53/ 53 x 31 +32
=53/32
k cho mình nha
32 x 53 -21 / 53 x 31 + 32
= ( 31 + 1 ) x 53 - 21 / 53 x 31 + 32
= 31 x 53 + 53 x 1 / 53 x 31 + 32
= 31 x 53 + 53 / 53 x 31 +32
= 53 / 32
Xong !