Question

Factoring special quadracics is when the first and last terms are perfect squares but in this expression the first and last terms are perfect squares and I am getting the wrong answer when i use the special rule

4x^2+20x+9

Answer 1

I am getting (2x+3)^2

Answer 2

\[(2x)^2+2(2x)(3)+(3)\]

Answer 3

\[(2x+3)^2\]

Answer 4

The first and the last terms are perfect squares but the trinomial is not a trinomial square because the middle term is wrong.

Answer 5

I know I am messing up because the middle term is not 20x but I want to know why because I sould be getting the right answer as the first and last terms are perfect squares

Answer 6

When the first and last terms are perfect squares, it alerts you to the possibility that it MAY be a perfect square trinomial. But you ALWAYS have to check out the middle ter to verify whether it truly is. And in your example...it isn't.

Answer 7

So just by looking at the fact that the first and last terms are perfect squares, I cannot conclude that I can apply the special rule, but unless the middle term is fine. Am I correct?

Answer 8

You are correct.

Answer 9

Thanks.

Answer 10

yw

Answer 11

The quadratic is still factorable and easily solved. (2x+9)(2x+1) giving two rational roots.