Question

Tính nhanh

53*39+47*39-53*21-47*21

Answer 1

53 x 39 + 47 x 39 - 53 x 21 - 47 x 21

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

= 39 x 100 - 21 x 100

= 100 x ( 39 - 21 )

= 100 x 18

= 1800

Answer 2

53 x 39 + 47 x 39 - 53 x 21 - 47 x 21

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

= 39 x 100 - 21 x 100

= 100 x ( 39 - 21 )

= 100 x 18

= 1800

ai k mik k lai

Answer 3

53 x 39 + 47 x 39 - 53 x 21 - 47 x 21

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

= 39 x 100 - 21 x 100

= 100 x ( 39 - 21 )

= 100 x 18

= 1800