b) x-(+8)=-9;
) x-8=-9;
j) 21=6-x


Răspuns :

x-(+8)=-9

x-8=-9

x=-9+8

x=-1

j) 21=6-x

x=6-21

x=-15

b) x =-9+8

x=-1

)x=-9+8

x=-1

j) x=6-21

×=-15