I read those F O I L comments above, and I now understand it
But I'm not from an English speakign country, and have therefore not had any experience with F.O.I.L.
Yes you can, it creates an equality. Without an equals sign your just sitting there simplifying an equation, which is what the content shows. You can stick an = 0 in there and not have to foil it.
0 = (x-3)(x+3)
x = 3 or -3.
No FOIL is necessary
Take Algebra again retard
Very good, thumb for you sir.
TO THOSE WHO DONT GET IT:
(X-2)(X+2)
X times X = X[s] (squared)
X times +2 = 2X
-2 times X = -2X
-2 Times +2 = -4
X[s] + 2X -2X -4 = X[s] -4
Never heard of that **** .
We just learned that each addend should be multiplied with both of the other addends.
But that's a step we normally just skipped.
(a+b)^2=a^2+2ab+b^2