x^25÷[(-x^2)^3]^4×(-x^3)^2÷(-x^2)^5
=x^25÷(-x)^2*3*4×(-x)^3*2÷(-x)^2*5
=x^25÷x^(2*3*4)×x^3*2÷(-x)^2*5
=x^(25-24+6-2*5)
=x^(-3)
=1/(x^3)
x^25÷[(-x^2)^3]^4×(-x^3)^2÷(-x^2)^5
=x^25÷(-x)^2*3*4×(-x)^3*2÷(-x)^2*5
=x^25÷x^(2*3*4)×x^3*2÷(-x)^2*5
=x^(25-24+6-2*5)
=x^(-3)
=1/(x^3)