a; -2001+(1999+2001)=-2001+1999+2001=1999
b;(43-863)-(137-57)=43-863-137+57=(43+57)-(863+137)=100-1000=-900
hok tốt
Bài làm
a) -2001 + ( 1999 + 2001 ) b) ( 43 - 863 ) - ( 137 - 57 )
= -2001 + 1999 + 2001 = -820 - 80
= [( -2001 + 2001 )] + 1999 = -820 + ( -80 )
= 0 + 1999 = -900
= 1999
# Chúc bạn học tốt #
a ) - 2001 + ( 1999 + 2001 )
= - 2001 + 1999 + 2001
= ( - 2001 + 2001 ) + 1999
= 0 + 1999
= 1999
b)
( 43 - 863 ) - ( 137 - 57 )
= 43 - 863 - 137 + 57
= ( 43 + 57 ) + ( - 863 - 137 )
= 100 + ( - 1000 )
= - 900
a) - 2001 + 4000
= ( 4000 + 2001 )
= 6001
b) - 820 - 80
= - ( 820 - 80 )
= - 740
Hk tốt,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
k nhé
a.(-2001+2001)+1999
=1999
b,43-863-137+57
=(43+57)-(863+137)
=100-1000=-900
a) -2001 + (1999+2001) = -2001 + 1999 + 2001 = ( -2001 +2001 ) + 1999 = 0 + 1999 = 1999
b) (43-863) - (137-57) = 43 - 863 - 137 + 57= (43+57)-(863+137)=100-1000=900