A few general questions and inquiries

Hey everyone,

I just joined and have a few math questions and "inquires" about certain things regarding math!

I had a quiz recently . The first question was regarding circles:

$\displaystyle x^2+64$, find the radius (I'm pretty sure it was radius, if not, please feel free to correct me). Can someone explain this?

Is the product of two binomials always a trinomial? Explain please.

Can someone give me some links/information to the following math related subjects:

- Completing the Square
- Equation of a Circle
- Difference of Squares
- Dividing, multiplying exponents
- Solving negative exponents

I'll add more 'topics' as they come to mind.

Thanks for the help, greatly appreciated.

-$\displaystyle NineZeroFive$