x^2+4x-8
(X+4)^2=6
could you help me please.
3 answers
If I only knew what the question was. Is there an equal sign on the first?
That trinomial is not a perfect square.
You can easily figure out if a trinomial is a perfect square.
x^2 + b x + c
if c = (b/2)^2
then
it factors to
(x + b/2 )^2
for example
(x + 3)^2 = x^2 + 6 x + 9
note that
9 = (6/2)^2
so if you were given
x^2 + 6 x + 9
you would do
(6/2)^2 which is 3^2 which is 9
so sure enought it is a perfect square
however if you are given
x^2 + 4 x - 8
(4/2)^2 = 2 ^2 = 4
which is NOT - 8 so it is not what you want
x^2 + b x + c
if c = (b/2)^2
then
it factors to
(x + b/2 )^2
for example
(x + 3)^2 = x^2 + 6 x + 9
note that
9 = (6/2)^2
so if you were given
x^2 + 6 x + 9
you would do
(6/2)^2 which is 3^2 which is 9
so sure enought it is a perfect square
however if you are given
x^2 + 4 x - 8
(4/2)^2 = 2 ^2 = 4
which is NOT - 8 so it is not what you want