(6x的3次方y的4次方z-4x的2次方z+2xy的3次方)÷(2xy的3次方)
=2x(3x^2y^4z-2xz+y^3)÷(2xy^3)
=(3x^2y^4z-2xz+y^3)÷(y^3)
=3x^2yz -2xz/y^3 +1(a的2次方-2bc)(-2ab)的2次方呢？(a的2次方-2bc)(-2ab)的2次方=(a^2-2bc)(4a^2b^2)=4a^4b^2-8a^2b^3c