Question

Determine whether the polynomial x^2+18x+81is a perfect-square trinomial. If it is, factor the trinomial.

Thanks!

Answer 1

This is how a perfect square expands out,
\[\Large\rm (a+b)^2=a^2+2ab+b^2\]

Can we write our polynomial in that form to show that it's a perfect square?\[\Large\rm x^2+18x+81\]
\[\Large\rm x^2+2(9x)+9^2\]Understand what I did there?

Answer 2

I think I understand! ^^
Thanks so much!

Answer 3

Cool c: