Question

Tính nhanh 

-65.(87-17)-87.(17-65)

 

Answer 1

-65 . 87 - (-65 . 17) - 87.17 + 87.65

= -65 . 87 + 65 . 17 - 87 . 17 + 87 . 65

= 87 . (-65 + 65) + 17 . (65 - 87)

= 87 . 0 + 17 . (-22)

= 0 + (-374)

= -374

Answer 2

=-65*87-(-65*17)-87*17-87*(-65)

=[-65*87-87*(-65)]-(-65*17+87*17)

=0-17*(-65+87)

=0-17*22

=0-374

=-374