# Thread: Making these two quantities equal?

1. ## Making these two quantities equal?

Hello,

How would I prove that $(Bx\cdot x)(Ax) = (Ax \cdot x)(Bx)$ if $Ax = \lambda Bx$?

I need to prove it without using the fact that I already know that $Ax = \lambda Bx$, because this is the second half of an iff proof, so I can't assume I have that knowledge.

Thanks!

2. ## Re: Making these two quantities equal?

Can you exactly write have you are supposed to do in the iff proof?