No it is not, however, 6x² - 5xy is.
x^2 + 6x + 9 cannot be simplified further. If x^2 + 6x + 9 = 0 then we can solve for x. x^2 + 6x + 9 can be broken into a binomial: (x+3)(x+3), which then gives us x = -3.
It is a quadratic expression in the variable x.
They add up to: 8x2
-4
The GCF is 2x.
It is: 6x2 or do you mean (6x)2 if so then it is 36x2
When factored it is: (6x-1)(6x+1)
8
We know that when you submit questions you aren't free to use the right format to make the mathematical terms crystal clear. It is likely that you mean "x squared times 6 plus x squared times 2", which is clearer. You can factor out the "x squared" and you will see that you get "x squared times 8". You COULD mean (6x) squared plus (2x) squared, which would be different. 6x times 6x would equal x squared times 36, so your answer will be much different.
2x
6x
x squared +6x +5 is a quadratic expression that can be factored as (x+1)(x+5)