Question

tinh nhanh

39.(19-13)-19.(39-13)

(42-69+17)-(42+17)

137.(-26)+26.137

-67.11

65.(-21)

Answer 1

-67x11=-67x(10+1)=-67x10+(-67)x1=-670+-67=-737

Answer 2

   39.(19-13)-19.(39-13)

=39.19 - 39.13 - 19.39 - 19.13

=0

     (42-69+17)-(42+17)

=42-69+17-42-17

=0-69+0

=-69

     137.(-26)+26.137

=137[(-26)+26]

=137.0

=0

      -67.11

=-67(10+1)

=-670+-67

=-737

      65.(-21)

=65[-(10+10+1)]

=-650+-650+-65

=-1365