Question

tính nhanh

53.39+47.39-53.21-47.21

Answer 1

53.39+47.39-53.21-47.21

= (53.39 - 53.21) + (47.39 - 47.21)

= 53. (39 - 21) + 47. (39 - 21)

= (39 - 21).(53 + 47)

= 18.100

= 1800

Answer 2

  53.39+47.39-53.21-47.21

= 39.( 53 + 47 ) - 21. ( 53 + 47 )

= 39.100 - 21. 100

=3900 - 2100

= 1800

       Chúc bạn học tốt nha !

 

 

Answer 3

Ta có: \(53\cdot39+47\cdot39-53\cdot21-47\cdot21\)

\(=39\cdot\left(53+47\right)-21\cdot\left(53+47\right)\)

\(=100\cdot18=1800\)