Mathematic formula

**Belgian General** · March 21, 2009, 01:21 PM

Hi there. I've always been terrible at remodeling mathematical formulas. Could you give a quick hand?

Say that

B = X * ( N * I )/ L

does that mean that

N = (B * L) / (X * I)

Is that correct? ^^
Thanks in advance : )

**Belgian General** · March 21, 2009, 02:06 PM

My excuses, I just noticed there's a sticky for these kinds of things. Sorry

**D.B. Cooper** · March 21, 2009, 10:07 PM

Glad I could help.

**Sphere** · March 22, 2009, 11:43 PM

Yes that is correct.

And don't listen to a guy called Simetrical. He is going to come in here and tell you he can invent a number system in which that is not correct. He is what you call a theoretical mathematician, and cannot be trusted.

**Simetrical** · March 23, 2009, 10:02 AM

I already said it was correct in the other thread. It's correct in any commutative semigroup, anyway, assuming X and I are invertible. The use of the "/" symbol for division would normally imply commutativity ― in non-commutative rings or semigroups, multiplication by inverses is normally used instead of division, for clarity. So the only time it would fail is if X or I were non-invertible. Admittedly this would occur pretty often in applications: in an equation of polynomials over a commutative ring, for instance, the conclusion wouldn't hold in general, only if X and I were units (i.e., scalars).

Note to Belgian General: ignore everything I just said. It's all quite correct, but it has no relevance to what you're doing and you don't have much hope of understanding it.

**Edratman** · March 23, 2009, 12:33 PM

Originally Posted by Simetrical

Note to Belgian General: ignore everything I just said. It's all quite correct, but it has no relevance to what you're doing and you don't have much hope of understanding it.

Cold,very cold.

**Copperknickers II** · March 23, 2009, 01:01 PM

True, though. What age is the guy, 15? And Sim probably has a masters in maths, from what i have seen of his posts.

**Simetrical** · March 24, 2009, 10:16 AM

Originally Posted by Copperknickers

True, though. What age is the guy, 15? And Sim probably has a masters in maths, from what i have seen of his posts.

I'm entering New York University's Ph.D. program in pure mathematics as a MacCracken Fellow this fall. What I just said is fairly basic undergraduate pure math.