ma ajutati va roog!!!!!

21.a) 23, 46, 69, 92
b){23, 46} {23,69} {23, 92}{46,69}{46,92}{69,92}
c){23, 46, 69}{23,69,92}{46,69,92}{23,46,92}
22. a)sau
b) si
c) si x nu apartine lui B
d) si x nu apartine lui A