12x13-12x11=? 17x27-27x19=? 19x15-19x11=?

2 câu trả lời

$\Longrightarrow$

12×13-12×11

=12×(13-11)

=12×2

=24

17×27-27×19

=27×(17-19)

=27×(-2)

=-54

19×15-19×11

=19×(15-11)

=19×4

=76

`12xx13-12xx11=12xx(13-11)=12xx2=24`

`17xx27-27xx19=27xx(17-19)=27xx(-2)=-54`

`19xx15-19xx11=19xx(15-11)=19xx4=76`