Different ways to write the logistic equation?

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I've been taught a very different equation to the normal logistic equation on the internet. Thing is, I don't know how to convert from one form to another so any help would be great.

The equations online is: $\frac{dp}{dt} = kP(1-\frac{p}{M})$, where $M$ is the carrying capacity.

The equation I was taught: $\frac{dp}{dt} = ap(\frac{k}{p}-p)$ where $\frac{k}{p}$ is the carrying capacity. Replacing this carrying capacity with $M$ gives:

$$\frac{dp}{dt} = ap(M-p)$$

I'm not sure how $M$ can be turned into a denominator of a fraction, such as the equation above.

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For the logistic equation

$$\frac{dp}{dt}=kp(1-\frac{p}{M})$$

replacing $M\rightarrow \frac{k}{p}$ gives

$$\frac{dp}{dt}=kp\left(1-\frac{p}{\frac{k}{p}}\right)=kp\left(1-\frac{p^2}{k}\right)$$ $$=kp\left[\frac{p}{k}\left(\frac{k}{p}-p\right)\right]=p^2\left(\frac{k}{p}-p\right)=ap\left(\frac{k}{p}-p\right)$$

where $a=p$


Or the other way around setting $\frac{k}{p}\rightarrow M$ in $\frac{dp}{dt} = ap(\frac{k}{p}-p)$ gives

$$\frac{dp}{dt} = ap(M-p)=ap\left[M\left(1-\frac{p}{M}\right)\right]$$ $$=aMp\left(1-\frac{p}{M}\right)=kp\left(1-\frac{p}{M}\right)$$

where $k=aM$, which is a constant of proportionality.