Ejercicio 10:
Si   U = { 1, 2, 3, 4, 5, 6, 7, 8, 9}              A = {x ∊ U/x  es par}
      B = { x ∊ U/ x es primo}                    D = {x ∊ U/ x no es divisor de 9}


Hallar :
∁ (A ⋃ B)
A ∆ B – A ∆ D
A ∆ B ∆ D

1)  A ⋃ B = { 2, 3, 4, 5, 6, 7, 8}
     ∁ (A ⋃ B) = U – (A ⋃ B)
     ∁ (A ⋃ B) = {1,9}

 2) A ∆ B = (A – B) ⋃ (B – A)
               = {4,  6, 8} ⋃ { 3, 5, 7}

 A ∆ B = { 3, 4, 5, 6, 7, 8}

 A ∆ D = (A – D) ⋃ (D – A)
            = ∅  ⋃ { 5, 7}

(A ∆ B) – (A ∆ D)  = {3, 4, 6, 8]

 3)A ∆ B ∆ D = (A ∆ B) ∆ D
           A ∆ B = ( A- B) ⋃ (B – A)
                     = {4, 6, 8} ⋃ {3, 5, 7}

 A ∆ B = {3, 4, 5, 6, 7, 8}

 A ∆ B ∆ D = { 3, 4, 5, 6, 7, 8} ∆ { 2, 4, 5, 6, 7, 8}

 A ∆ B ∆ D = {3} ⋃ {2}

 A ∆ B ∆ D = {2,3}