TRẢ LỜI

1. 1) A=[−4;4]B=(−4;9]A∪B=[−4;9]R∖(A∪B)=(−∞;−4)∪(9;+∞)A∩B=(−4;4]A∖B=−4B∖A=(4;9)

   2)

   A=[−2;2]

   B=(−1;4)

   A∪B=[−2;4)

   R∖(A∪B)=(−∞;−2)∪[4;+∞)

   A∩B=(−1;2]

   A∖B=[−2−1]

   B∖A=(2;4)

   3)

   n(A)=25; n(B)=29; n(A∪B)=41

   n(A∩B)=n(A)+n(B)−n(A∪B)=25+29−41=13

   n(A∖B)=n(A)−n(A∩B)=25−13=12

   n(B∖A)=n(B)−n(A∩B)=29−13=16

   Trả lời
2. $1)$

   $A = [-4;4]$

   $B= (-4;9]$

   $A\cup B = [-4;9]$

   $R\backslash (A\cup B)= (-\infty;-4)\cup (9;+\infty)$

   $A\cap B = (-4;4]$

   $A\backslash B = {-4}$

   $B\backslash A = (4;9)$

   $2)$

   $A = [-2;2]$

   $B = (-1;4)$

   $A\cup B = [-2;4)$

   $R\backslash (A\cup B)= (-\infty;-2)\cup [4;+\infty)$

   $A\cap B = (-1;2]$

   $A\backslash B = [-2-1]$

   $B\backslash A = (2;4)$

   $3)$

   $n(A)= 25;\ n(B)= 29;\ n(A\cup B)= 41$

   $n(A\cap B)= n(A) + n(B)- n(A\cup B)= 25 + 29 – 41 = 13$

   $n(A\backslash B)= n(A)- n(A\cap B)= 25 – 13 = 12$

   $n(B\backslash A)= n(B)- n(A\cap B)= 29 – 13 = 16$

   Trả lời