here I'm asked to solve this quadratic
equation using the quadratic formula but
certainly we can see 3 or negative 3
squared is 9 9 minus 9 is 0 so my guess
and check we know the answer but let's
use the quadratic formula anyways so
here it is quadratic formula solves any
quadratic equation gives you the two
solutions there in this case a is 1
that's the coefficient on x squared
notice there's no B term so the
coefficient there we can think of it as
0 and C is negative 9 let's go ahead and
substitute in those values in here I did
that negative B so negative 0 is just 0
leaves me with plus or minus the square
root now 0 squared is 0 0 plus or minus
anything is just that number so negative
4 times negative 9 is 36 all divided by
2
36 perfect square so we get plus or
minus 6 divided by 2 is plus or minus 3
so there's the two solutions we sort of
guessed at so my solutions here are
negative 3 & 3
