3x^2 * (2x^2 + 4x - 5)

C.1 
a.3x^2*(2x^2+4x-5)
b.(2x-y)*(2xy+3y^2+x)
c.6x^4y^3-12x^3y^4+36x^3y^3)chia (-6x^2y^2)