Alegbra- How can I solve #5?

3

9

21

Step-by-step explanation:

For the first one use the law of total probability

B=A∩B+A'∩B

12=9+A∩B

A∩B= 3

For this one you should use demorgans law and the union formula

(A'∩B')=(AUB)'

AUB= A+B-A∩B

6+12-3=15

15'= 24-15 = 9

For this one use demorgans law again

(A'UB')=(A∩B)'

(A∩B)'= 24-A∩B= 24-3= 21

for finding the midpoint of any given 2 pair of points simply add the respective x coordinates with other x coordinate and the y coordinate with other y coordinate and divide them by 2

in your question it will be :

(3+1)/2 for the x coordinate of mid point i.e 2

[8+(-4)]/2 for the y coordinate of midpoint i.e 2

so coordinates of mid point of points (3,8) and (1,-4) will be (2,2)