Question

tính nhanh - 2001 + ( 1999 + 2001 )

Answer 1

-2001+2001+1999

=0+1999

=1999

Answer 2

Bằng 6001

Answer 3

Nghiêm Phương Thuý:

-2001 + (1999 + 2001)

= -2001 + 2001 + 1999

=            0         + 1999

= 1999

:3, Chúc bạn hok tốt!!!

Answer 4

\(-2001+\left(1999+2001\right)\)

\(=-2001+1999+2001\)

\(=\left(2001+2001\right)+1999\)

\(=0+1999=1999\)