Question

Which of the following is a perfect square trinomial?

Answer 1

Answer:

$x^2-5x+6\\(x-3)(x-2)$

$x^2-3x+4\\(x-4)(x+1)$

$x^2+20x+100\\(x+10)(x+10)\\(x+10)^2$

That's the answer

$x^2+14x-49\\x(x+14)-49$

Only $x^2+20x+100$ is a perfect square trinomial