Answer:
(2x - 5y)(2x + 5y)
Explanation:
1) Consider the Polynomial as such: 4x^2 + 0xy -25y^2
2) Consider also that (4x^2 + 10xy) + (-10xy - 25y^2) would be the best way to arrange the factoring.
3) then you take 2x out from each equation to get: (2x)(2x+10y) (-2y -25y^2)
4) then you take -5y out to get: (2x-5y)(2x+5y)