here we're going to solve this two ways
the first method is the method we've
been using all along and that's by
factoring
so notice x squared minus 9 is
difference of squares a plus B times a
minus B okay X plus 3 times X minus 3
and then set each factor equal to 0 this
so this is the familiar way to do it
we've been doing this all along x equals
negative 3 or x equals 3 so here I get
two solutions certainly you can check
those plus or minus 3 when I plug in
plus or minus 3 and squared I get 9 9
minus 9 is 0 now let me show you a new
method for this section it's called
extracting roots the first step for
extracting roots is to isolate the
square so we'll do that here by adding 9
to both sides that leaves me x squared
equals 9 okay and then once the square
is by itself we can then take the square
root of both sides now when I do that
here I get x equals 3 notice negative 3
is also solution so that not to lose
this second negative solution when you
take the square root of outside you have
to put the little plus or minus there
indicating that positive 3 will work
also negative 3 will work so you get the
same two solutions as long as you
remember whenever you take the square
root of both sides you have to include
the plus or minus
