How to go from phasor to polar/rectagular with impedance

Okay so I'm a little confused about how to go from phasor to polar etc. I'm specifically curious about the impedance equation. I know Z=V/I, and I have gotten to Z=1/(.33+j0.5). I found the angle to be 56.33 using atan(.5/.33). This is correct. But I'm looking at some examples in the book and I'm confused.

for example:
they have 50/(1+j5) = 1.92 - j9.62, I'm not sure how they got to the 1.92 or the 9.62.
for that problem,
w= 10^4 rad/s r1, L=10mH, R1= 100 ohms, R2=50 ohms, C= 10 microfarads

they did Zparallel = R2||1/jwc = (R2*(1/jwC))/(R2+(1/jwC) = R2/(1+jwcR2) = 50/(1+j5) I follow that part. I don't know how they then went to 1.92-j9.62...

For complex numbers, to do a multiplication or division (such as inversion), convert first to polar. To do addition and subtraction, first convert to rectangular.

(1+j5) = 5.0990 angle(78.6901deg)
To invert the polar form, invert the amplitude and negate the angle.
1/(1+j5) = (1/5.0990)angle(-78.6901deg)
= 0.1961angle(-78.6901deg)

In your case, the problem is:
50/(1+j5) = (5/5.0990)angle(-78.6901deg)
=9.8058angle(-78.6901deg)

Convert back to rectangular:
=1.92-j9.62