I want my money and i want it now !!!!!!

Let us take the number of employees at the beginning as $n$ and their original share of the money as $x$ . So, from the question, we get ----

$x=\frac{4800}{n} \implies nx=4800$ .....(i) and,

$x+80=\frac{4800}{n-3}$

$\implies nx+80n-3x-240=4800 \implies 4800+80n-3x-240=4800 \text{[From (i)]} \implies 80n-3x-240=0$ .....(ii)

Putting value of $x=\frac{4800}{n}$ from (i) in equation (ii), we get ------

$80n-3(\frac{4800}{n})-240=0$

$\implies 80n-3(\frac{4800}{n})=240$

$\implies \frac{80n^2-14400}{n}=240 \implies 80n^2-14400=240n$

$\implies 80n^2-240n-14400=0$

$\implies n^2-3n-180=0 \implies (n-15)(n+12)=0 \implies n=\boxed{15}\text{ [Neglecting n+12=0, n=(-12) as n cannot be (-ve)}$