[tex](-4m^8n^5)^2=(-4)^2(m^8)^2(n^5)^2=16m^{8\cdot2}n^{5\cdot2}=16m^{16}n^{10}\\\\Used:\\\\(ab)^n=a^nb^n\\\\(a^n)^m=a^{nm}[/tex]
