That expression is the square of (5x + 1), so both of its factors are the same.
(5x + 1)2 = 25x2 + 10x + 1
That expression can not be factored.
4x(10x + 1)
3x2 + 10x + 3 = (x + 3)(3x + 1).
3x2+10x+7 = (3x+7)(x+1) when factored
(x+1)(x+9)
(2x - 1)(5x + 8)
(x+1)(x+9)
5x + 10x doesn't need factorization as you can just add them up (5x+10x=15x). However, if you really want to, 5x+10x=5x(1+2)=5x(3)=15x
-1
If that's + 1, the answer is (10x + 1)(10x + 1) or (10x + 1)2 If that's -1. it gets ugly in a hurry.
3x2 + 10x + 3 = (x + 3)(3x + 1).