I'm not sure why I can't see what step is occuring here, but I could use some help:(adsbygoogle = window.adsbygoogle || []).push({});

[tex]G(s) = \frac {30}/{(s^2 + 6s +20)}[/tex]

[tex]H(s) = \frac {k} /{s+8}[/tex]

Characterisic equation: [tex]1+ G(s)H(s)[/tex]

So,

[tex]1 + \frac ({30k} /{(s^2+6s+20)(s+8))} = 0[/tex]

Then, the step I'm not sure about:

[tex](s^2+6s+20)(s+8) + 30k = 0[/tex]

How do I get to that step? For some reason I can't see the simple algebra that is used.

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# Missing a step:

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