Well i couldn't go to school today for various reasons.

So i'm trying to teach myself some stuff and am having trouble understanding the method.

The method goes like this :

if

then

and

Ok, i get that

and i also get you can use elimination to then solve this...but i don't get what they've done...

By eliminating B from the first and second equation...they get

This is where im confused...where the hell do they even get

from?

Note: Its meant to be x to the power of a half...but latex doesnt like it lol.

Thank-you