-2 < a ≤ 1 ⇒ a = - 1 , 0 , 1
A = { 2⁻¹ , 2⁰ , 2¹ } = { 1/2 , 1 , 2 }
2≤ b < 5 b = 2 , 3 , 4
y = 3 ² ⁻³ = 3 ⁻¹ = 1/3 ; y = 3³⁻³ = 3°=1 ; y = 3⁴⁻³ = 3 ¹ =3
B = { 1/ 3 ; 1 , 3 }
AUB= { 1/3 ; 1/2 ; 1 ; 2 ; 3 }
A - B = { 1 /2 ; 2 } B -A = { 1/3 ; 3}
A Π B ={ 1}
AxB= { (1/2;1/3 ) ; (1/2 ; 1) ; ( 1/2 ;3) ; (1 , 1/3) ;(1,1) ; (1 ,3) ;(2 ; 1/3) ;
(2,1) ; (2 ,3) }