Tính: (4x^5 - 8.x^3) : (-2x^3); (2x^3 - 5x^2 - x + 1) : (2x + 1)

Cac ban oi day la BT TEt cua minh, cac ban giup minh voi xin cam on nhieu :D
1, 10x^3.y^2.z : (-4x.y^2.z)
2, ( 4x^5 - 8.x^3 ) : ( -2x^3 )
3 ( 2x^3 - 5x^2 - x + 1) : ( 2x + 1 )
4, ( x^4 - 2x^3 - 1 + 2x ) : ( x^2 - 1 )
5, 1/3.x^3.y^4.( 2xy^3 - 1 )
Cac ban lam on giup minh voi nhe T_T