Answer:
A. 1/5k - 2/3j and -2/3j +1/5k
Step-by-step explanation:
A. 1/5k - 2/3j and -2/3j +1/5k
B. 1/5k - 2/3j and -1/5k +2/3j
There is a change in the signs of each term
1/5k changed to -1/5k
-2/3j changed to +2/3j
Not equivalent
C. 1/5k - 2/3j and 1/5j - 2/3k
There is a change in the variables
1/5k changed to 1/5j
-2/3j changed to -2/3k
D. 1/5k - 2/3j and 2/3j - 1/5k
The is a change in the signs of each term
1/5k changed to -1/5k
-2/3j changed to +2/3j
The only equivalent expression is
A. 1/5k - 2/3j and -2/3j +1/5k
Answer:

Step-by-step explanation:
A complex number is defined as z = a + bi. Since the complex number also represents right triangle whenever forms a vector at (a,b). Hence, a = rcosθ and b = rsinθ where r is radius (sometimes is written as <em>|z|).</em>
Substitute a = rcosθ and b = rsinθ in which the equation be z = rcosθ + irsinθ.
Factor r-term and we finally have z = r(cosθ + isinθ). How fortunately, the polar coordinate is defined as (r, θ) coordinate and therefore we can say that r = 4 and θ = -π/4. Substitute the values in the equation.
![\displaystyle \large{z=4[\cos (-\frac{\pi}{4}) + i\sin (-\frac{\pi}{4})]}](https://tex.z-dn.net/?f=%5Cdisplaystyle%20%5Clarge%7Bz%3D4%5B%5Ccos%20%28-%5Cfrac%7B%5Cpi%7D%7B4%7D%29%20%2B%20i%5Csin%20%28-%5Cfrac%7B%5Cpi%7D%7B4%7D%29%5D%7D)
Evaluate the values. Keep in mind that both cos(-π/4) is cos(-45°) which is √2/2 and sin(-π/4) is sin(-45°) which is -√2/2 as accorded to unit circle.

Hence, the complex number that has polar coordinate of (4,-45°) is 
Assuming the man works 8 hours straight without breaks:
25% is the same as 1/4 of something.
So, we just have to figure out what 1/4 (one quarter) of 8 equals.
You can think of it as a pizza cut into 8 slices. One slice is equivalent to one hour for the patrolman.
If we take away 1/2 (half) of the pizza, we have 4 slices, right? Since we start with 8 slices, half of that equals 4 slices. In other words, 50% (half) of the pizza = 4 slices.
Now, 25% (one quarter) of the pizza will equal half of what is left:
If we know that 50%=4 slices (or 4 hours), then 25% must be 2 slices (or 2 hours).
That's it! 25% of 8 hours = 2 hours.
***So, the patrolman spends 2 hours each day completing paperwork.***
Lets check our work:
We know 8 hours (or 8 slices)= 100%
(We know this because
8 slices = 1 whole pizza, or 100% of a pizza. Similarly,
8 hours = 1 whole shift or 100% of the man's shift ).
So
25% + 25% + 25% + 25% = 100%
If 100% of the mans shift = 8 hours:
2+2+2+2 = 8
It checks out!
Hope this helps!