x^2/4 + 2xy + 4y^2

x^2/4 + 2xy + 4y^2
- x^2 + 10x - 25
-16a^4b^6 - 24a^5b^5 - 9a^6b^4
25x^2 - 20xy + 4y^2
25x^4 - 10 x^2y + y^2