The given expression is
[tex] 3\sqrt{125x^4} [/tex]
We have to write it in a different way and for that, we have to check the factors of 125 and x^4 .
And factors of 125 are 25 and 5.
[tex] 3\sqrt{25*5*(x^2)^2} [/tex]
Radical 25 equals to 5 and radical [tex] x^4 [/tex] is [tex] x^2 [/tex].
So we will get
[tex] 3*5x^2 \sqrt{5} = 15x^2 \sqrt{5} [/tex]
And that's the another way to write the given expression .