Question

1) а^2 x^2-y^4

2)a^2 y^2-x^6

3) c^2-4c+4-9x^2

4)c^2-6c+9-4x^2

5)4c^2+20c+25-9a^2

6)y^2 x+y+yx^2+x+4yx+4

7)3x^2+2x-xy-2y^2+y^3-3xy^2

8)x^2+x-xy-y^2+y^3-xy^2

9)a^2x+a+ax^2+x+2ax+2