What does it mean to factor a polynomial?

Answer 1

It is the same as factoring a number, seeing what you can divide out with no remainder
For example
x^2-y^2

I can divide that by (x+y)
and get (x-y)
so
x^2-y^2 = (x+y)(x-y)
just like
10 = (5)(2)

Try it with long division