Question

Determinati multimea A={x ∈ Z  | | 2+x | =5 }

Answer 1

|2+x|=5
2+x=5
x=3 

2+x=-5
x=-5-2
x=-7

A={3, -7}

Answer 2

2+x=5=>x=3
2+x=-5=>x=-7
=>x∈{3;-7}