A negative exponent just means that the base is on the wrong side of the fraction line, so you need to flip the base to the other side. For instance, "x^-2" just means "x2, but underneath, as in 1/x^2.
-4^-2 means the power -2 is only applied to 4 and not the negative sign. -4^-2 = -(4^-2), which is equal to -1/16.
Whereas, (-4)^-2 means the power -2 affects on both negative sign and 4. For example, (-4)^2 is equal to (-4 * -4) which is just 16. Moving on, with (-4)^-2 equals to 1/(-4*-4) = 1/16.
//Hope this helps.
Answer:
(a)= option 3
(b)= option 3
Step-by-step explanation:
(A) It is given that a sequence is defined by the recursive function
and 
Now, substituting the value of n=2 in above equation,



Again putting n=3,



Putting n=4,



Putting n=5,



Putting n=6,



Putting n=7,



Hence, option 3 is correct.
(B) The given sequence is :
5, -10, 20, -40, 80.....
Since, the given sequence is GP, therefore
and r=-2
The nth term is given by:

For fifteenth term, put n=15 in above equation, we get

=
=
Hence, the fifteenth term is 81920.
Option 3 is correct.
Bar graph
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a. The events are mutually exclusive, so

b. For the same reason,

Another way to see this is to use the result from part (a), and the inclusion/exclusion principle:

and the right side reduces to 0.
c. Same as (b),

d. Same as (b),

We can also use the distributivity rule for unions and intersections to write

e. If the
is the complement of
, then by DeMorgan's law,
