Question

- (-7-9-20) + (-2+11-21) =

Answer 1

=-(-16-20)+(-2+11-21)=-36+(9-21)=36+(-12)=36-12=24
este corect 
coroana

Answer 2

1.-7-9=-7+(-9)=-16
2.-16-20=-16+-20=-36
3.-2+11=-(11-2)=-9
4.-9-21=-9+(-21)=-30
30+(-30)=0
nu ştiu dacă e corect..