=(50+40+30+60)-(51-41-31)
=180+21
=201
nhóm (50-51)+(40-41)+(30-31)+60
=-1+-1+-1+60
=57
chúc bạn học tốt!
50 - 51 + 40 - 41 + 30 -31 + 60
= ( 50 + 40 + 30 + 60 ) - ( 51 - 41 - 31 )
= 180 + 21
= 201
50-51+40-41 + 30-31+60
=50-50-1+40-40-1+30-30+1+60
=0+60-1-1-1
=57
ok xong