Completely factor the polynomial. 4x^2 20x 25

I use the railroad method so here's how I would solve it:

4 x 25 = 100

10 x 10 = 100, 10 + 10 = 20

(x + 10/4) (x + 10/4)

(x + 5/2) (x + 5/2)

The answer should be: (2x + 5) (2x + 5)

It can be checked:

2x x 2x = 4x^2

2x x 5 = 10x

5 x 2x = 10x

5 x 5 = 25

4x^2 + 20x + 25

So yes, the answer would be (2x + 5) (2x + 5)