number 19 slapped me

[white river]

THE HELL? it was all normal maths then NUMBER 19!!! (Its combined variation)

Help

[undone fog]

Well, we have S ~ r and S ~ h. So, S ~ rh, which means S/(rh) = const.
So:
S1/(r1h1) = S2/(r2h2)
Thus:
S2 = (r2/r1)(h2/h1)S1
We have S1 = 240π cm^2, r1 = 12 cm, h1 = 10 cm, r2 = 8 cm, h2 = 9 cm. Substitute to get S2.

[undone fog]

What?

[white river]

Imma read it slowly cuz i didnt understand anything

What dies subsitute mean or what it does i only remember how to do stuff nkt whats the name

[undone fog]

Change the variables to their values.

[white river]

Ahhhh

Not tryna sound rude but

I didnt understand anything

[undone fog]

Well, ok...
Which part, exactly?

[white river]

To be honest..

Everything

[undone fog]

Well, I can't help you if you don't say what you don't understand.

[white river]

I just wanna know.. is this combination variation?

[undone fog]

Combined variation? Well, yeah, since S is directly proportional to r and to h.

[white river]

Oohhh

Just wait lemme re read what your formula