Question

(3-x)(3+x)-6=2 calculate:

Answer 1

[3-x]·[3+x]=8
⇒x=-1∈Z;
⇒3-[-1]=3+1=4;
⇒3+[-1]=3-1=2;
⇒4·2=8⇒adevarat;
sau x=1∈N;
⇒3-1=2;
⇒3+1=4⇒2·4=8·adevarat[inmultirea este comutativa];
⇒x=[-1,1];