Remove all perfect squares from inside the square root 25x^4

The answer:

the main rule:

for all value positive of a real b, √b² = b, and √b*c = √b * √c, if c is a real positive

let A=√25x^4, we know that 25x^4=5² * x² * x²

therefore,

√25x^4 = √5² * x² * x² = √5² √x² √x² = 5 * x*x = 5x²

the final answer is A=√25x^4=5x²