Answer:
[tex]\large\boxed{2(5m^4n^{-1})^3=250m^{12}n^{-3}=\dfrac{250m^{12}}{n^3}}[/tex]
Step-by-step explanation:
[tex]\text{Use}\\\\(ab)^n=a^nb^n\\\\(a^n)^m=a^{nm}\\\\a^{-n}=\dfrac{1}{a^n}\\-------------------\\\\2(5m^4n^{-1})^3=2(5)^3(m^4)^3(n^{-1})^3=2(125)m^{3\cdot4}n^{-1\cdot3}=250m^{12}n^{-3}=\dfrac{250m^{12}}{n^3}[/tex]
