perform and simplify completely (x-2)^2

Question

anonymous · Answer

x^2-4x+4

anonymous · Answer

how did you get to that?

anonymous · Answer

you can remember the formula (a-b)^2=a^2-2ab+b^2
or do the multiplication (x-2)(x-2)

anonymous · Answer

is the multimplication the "foil" method?

anonymous · Answer

yes.

anonymous · Answer

ok, well that I know how to do, but i get confused as when to use it

anonymous · Answer

Whenever you have a binomial that is squared for example, (x+3)^2 what it really means is (x+3)(x+3).  So when you see this (x+3)^2 or whatever rewrite it.  It's even better if you can remember the patterns like Andras so graciously posted but no worries if you don't, you just have to take the extra step and work it through.
 The squared symbol is like having code for saying "multiply this group by itself.  Just like an x^2 is an "x" times an "x", it's really the same principal.