If linear estimate r= Is it correlation causation or neither
Whats the possible lurking variable
And the reasoning:

Let's call the lesser number x and the other one x+8

Explanation:

The product x⋅(x+8)=240→

Or:  x2+8x=240→

We can rework this by subtracting 240 from both sides:

x2+8x−240=0

Now we factor −240 into two factors that add up to 8
After some trying we find 20and−12

The equation turns into

(x+20)(x−12)=0

→x=−20orx=12

So the pairs of numbers will be:

−20and−12 or +12and+20