(-3x^2y^2z)÷9x^4*y^5*x^3(x^2y)^2
=-3x^2y^2z*x^3x^4y^2/9x^4y^5
=-3x^9y^4z/9x^4y^5
=-x^5z/3y(x²-y²+x+y)÷(x+y)，这题求你了，给你10分(x²-y²+x+y)÷(x+y)=[(x-y)(x+y)+(x+y)]/(x+y)=(x+y)(x-y+1)/(x+y)=x-y+1