Factor completely the following questions: Note: If a question cannot be factored, state "prime" or "non-factorable" and explain the reason why.

1) ²+421

2) ²9+10

3) ²++20

4) ²+56²

5)2²98²

6)1211+2²

7)3⁴8³+4²

8)9²+ 42 15²

9)32⁴³+ 16m³⁴+ 2²⁵

apply substitution on factoring.

10)2( + 7)² 5( + 7) 25

*let = + 7and continue to factor*

11)6(2 1)²+ 34(2 1) + 20

*let_____ = ________________

12)( )²+ 2( ) + 1

*let = and continue to factor