New rule formula in maths

So I was doing some maths the other day and I cam up with a rule: a^b X c^-d=a^b/c^d
This basicaly means that you can take any number and substitue it in and it should work.

Now My teacher says she has never seen that before and she asks me where I got it from. So there is a chance I saw this somewhere and it was in my sub concious but has anyone seen this formula before? Thanks

Who invented it? Where have you seen it?

I'm not sure who invented it but this is one of the laws of exponents. a^-b = 1/a^b

So, a^b X c^-d = a^b/c^d

This is an application of the law of indeces and is fairly well known (sorry you didn't invent it but you're absolutely correct what you say is true).

You see c^-d = 1/c^d - this is the law of indeces

So a^b * 1/c^d = a^b/c^d - this is just the standard rules of multiplying fractions.

As for who invented it - there were a lot of people involved from Mohammed ibn Musa al-Khwarizm who came up with the idea of letter substitution to John Napier who worked a lot with indeces and came up with logarithms and many many people in between, so it's hard to say exactly who came up with it. Your "new" rule however is correct, it's just not new.

hahhahahahh

yarr yeh to 8th class algebra hai