Please help with expression and type of quadratic:

x^2+2x+3
x^2+11x+10
14x^2-4x+16
4x^2-20x+25
x^2-36
10x^2+19x+6
Possible answers are:
Difference of two squares
a greater than 1, Grouping
a=1
Prime
Greatest common factor only
Perfect square trinomial
This expression cannot be factored as it is.
This expression can only have a factor taken out of each term and the remaining trinomial cannot be factored further.

There are more answers but it is to much writing. I understand a little of it but not all of it yet.

1. x^2+2x+3 - This expression cannot be factored as it is.

2. x^2+11x+10 - a greater than 1, Grouping
3. 14x^2-4x+16 - a greater than 1, Grouping
4. 4x^2-20x+25 - Perfect square trinomial
5. x^2-36 - Difference of two squares
6. 10x^2+19x+6 - a greater than 1, Grouping