Solution :
We have to prove that
(De-Morgan's law)
Let
then
and 
and so
and
.
Thus,
and so 
Hence,
.........(1)
Now we will show that 
Let
⇒
Thus x is present neither in the set A nor in the set B, so by definition of the union of the sets, by definition of the complement.
and 
Therefore,
and we have
.............(2)
From (1) and (2),
Hence proved.
Answer:
Step-by-step explanation:

Hint:

Answer:
mx+b+a= x-12x=0.88x
Step-by-step explanation:
Sum of all interior angles of a polygon
180( n - 2) where n = number of sides in the polygon
now, if n = 19, the polygon has 19 sides, then 180( 19 - 2)
Answer: i - j - k
Step-by-step explanation:
Taking the cross product between two vectors will give you a third vector that is orthogonal(perpendicular) to both vectors.
<1,1,0> x <1,0,1>
![det(\left[\begin{array}{ccc}i&j&k\\1&1&0\\1&0&1\end{array}\right] )](https://tex.z-dn.net/?f=det%28%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Di%26j%26k%5C%5C1%261%260%5C%5C1%260%261%5Cend%7Barray%7D%5Cright%5D%20%29)
the determinate of the matrix: <1,-(1),-1>
or: i - j - k