You answer is the third option
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.

Getting the central area of a polygon is not possible. Probably the question refers to the central angle. In a a regular polygon, getting the central angle is that you need to use the formula.
Central Angle of a polygon = 360 degrees / number of sides of a polygon.
Why 360 degrees? Because, a circle has a total of 360 degrees. And a circle is a polygon with no sides.
Answer:
x=115 y=65
Step-by-step explanation:
You get 115 for X because angle x is vertical to 115 degrees.
You get 65 because y is supplementary to x, and 180-65=115.