Question

Tính nhanh

a) - 2001 + (1999+2001)

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

Answer 1

a) - 2001 + (1999+2001)

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

giải

a, (-2001+2001)+1999=0+1999=1999

b, (863+157) -( (57+43)=1000-100=900

tick nhé

 

Answer 2

a)-2001+(1999+2001)

=(-2001+2001)+1999

=0+1999

=1999

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

   =(43+57)-(863+137)

   =100-1000

   =-900

Answer 3

a) bang 1999

b) bang -900

tick nha