Question

tính nhanh : a) 786 -549 + 548 b) ( 647 +835 ) - ( 645 + 833 )

Answer 1

a ) 768 - 549 + 548

= 219 + 548

= 767

b ) ( 647 + 835 ) - ( 645 + 833 )

= 1482 - 1478

= 4

Answer : a ) 767

b ) 4

Answer 2

a) 786 -549 + 548

  =786+(548-549)

   =786-1=785

b) (647+835)-(645+833)

 =647+835-645-833

= (647-645)+(835-833)

=2+2=4

k cho mk nha

Answer 3

a,786-549)+548=237+548=785

b, =(647+833)-(835+645)= 1480-1480= 0