pt -2 < a </ 1 , a apartine {-1, 0, 1}
din a = -1 => 2⁻¹ = 1/2
a = 0 => 2⁰ = 1
a=1 => 2¹ = 2
Deci A={1/2, 1, 2}
pt 2 </ b < 5, b apartine {2,3,4}
din b = 2 => 3²⁻³ = 3⁻¹ = 1/3
din b = 3=> 3⁰ = 1
din b = 4=> 3⁴⁻³ = 3
deci B ={1/3, 1, 3}
AUB={1/3, 1/2, 1, 2, 3}
A ∩B={ 1}
A\B ={ 1/2, 2}
B\ A={1/3, 3}
