Answer:
Step-by-step explanation:
[logical equivalence]
[morgan laws]
if
is true, then
is true and
is too.
with
true, then
is false [double denial]
In the first equivalence it follows that
is true [identity law]
Then it can be concluded that 
Answer: I think that the sandwich is $4.25 (I'm not sure)
Answer:
A
Step-by-step explanation: