# math,help

posted by
**jasmine20** on
.

Is this trinomial a perfect square

x^2-6x+9

if the trinomial starts with x^2 and 1/2 of the middle term coefficient squared equals the last term, then it is a perfect square.

tell me what you found.

i thought it was not a perfect square. because i tried factoring it but it won't come out.am i wrong then

expand (x+3)^2

(x+3)(x+3)

x^2+3x+3x+9

x^2+6x+9

but in the original is x^2-6x+9

(x+3)^2 is incorrect. It is (x-3)^2:

x^2-3x-3x+9

x2-6x+9

and there is your answer.

Do you get it?

(x-3)(x-3)

x^2-3x-3x+9

x^2-6x+9

therefore it is a perfect square is this correct then

sorry emily, of course I meant (x-3)^2, it was a typo. sorry, its getting late where I am.

Yes it is. Good job!