Hi again (Headbang)

I am so frustrated - I haven't posted in a while and today this is my 2nd post.

First time I'm doing Descartes rule of signs and it just doesn't make sense.

I get the part where you take the polynomial and count the sign changes to get the max positive number of 0's

The problem comes it with the P(-x) where you then change the polynomial - i do this as I've done everything else where 2 -'s make a + but for some reason this seems to be wrong?

I have a question I have to do but I'd like someone to explain another random example to me - then I'd like to try mine and have you check it for me?

Thanks for all the help guys you rock!

Janine