namely, let's rationalize the denominator in the fraction, for which case we'll be using the <u>conjugate</u> of that denominator, so we'll multiply top and bottom by its <u>conjugate</u>.
so the denominator is 5 + i, simply enough, its conjugate is just 5 - i, recall that same/same = 1, thus (5-i)/(5-i) = 1, and any expression multiplied by 1 is just itself, so we're not really changing the fraction per se.

Answer - natural
A sequence is a function whose domain is the set of natural numbers.
Answer:
(a)
and
are indeed mutually-exclusive.
(b)
, whereas
.
(c)
.
(d)
, whereas 
Step-by-step explanation:
<h3>(a)</h3>
means that it is impossible for events
and
to happen at the same time. Therefore, event
and
are mutually-exclusive.
<h3>(b)</h3>
By the definition of conditional probability:
.
Rearrange to obtain:
.
Similarly:
.
<h3>(c)</h3>
Note that:
.
In other words,
and
are collectively-exhaustive. Since
and
are collectively-exhaustive and mutually-exclusive at the same time:
.
<h3>(d)</h3>
By Bayes' Theorem:
.
Similarly:
.
I helped my friend pull out her tooth I asked for 20% of the money she got from the tooth fairy I'm and my friend were walking down the street I found a pile of pennies and my friend asked for 50% of the pennies because we found them together