Question

tính nhanh

-2001 +( 1999 + 2001 )

( 43 - 863 ) - (1 37 - 57 )

Answer 1

-2001+(1999+2001)

=[-2001+2001]+1999

=0+1999

=1999

(43-863)-(137-57)

=43-863-137+57

=-820-137+57

=-957+57

=-900

k nh mk làm nhanh nhất

Answer 2

1)= -2001 + 2001 + 1999

  = 0 + 1999

  = 1999

2) chưa hiểu rõ :)))))

Answer 3

a) -2001 + ( 1999 + 2001 )

= [ 2001 + ( - 2001) ] + 1999

= 0 + 1999

= 1999

b) ( 43 - 863 ) - ( 137 - 57)

= - 820 - 80

= -900

k mình nhé  Anh Phạm

Answer 4

a)-2001+(1999+2001)

=(-2001+2001)+1999

=0+1999

=1999

b)(43-863)-(137-57)

=(-820)-(137-57)

=(-820-137)+57

=(-957)+57

=900