Use these properties:
#x^0=1qquadqquad# (Anything to the power of #0# is #1#)
#x^color(red)m/x^color(blue)n=x^(color(red)m-color(blue)n)#
#1/x^color(red)m=x^(-color(red)m)#
Now here's the problem:
#color(white)=(color(red)(m^-2)color(green)(n^-4))/(color(blue)((2m^-2n^4p^-3)^0)*color(purple)2color(red)(m^2)color(green)(n^-4)color(orange)(p^-1))#
#=(color(red)(m^-2)color(green)(n^-4))/(color(blue)1*color(purple)2color(red)(m^2)color(green)(n^-4)color(orange)(p^-1))#
#=(color(red)(m^-2)color(green)(n^-4))/(color(purple)2color(red)(m^2)color(green)(n^-4)color(orange)(p^-1))#
#=color(purple)1/color(purple)2*color(red)(m^-2)/color(red)(m^2)*color(green)(n^-4)/color(green)(n^-4)*1/color(orange)(p^-1)#
#=color(purple)1/color(purple)2*color(red)(m^-2)/color(red)(m^2)*color(green)(n^-4)/color(green)(n^-4)*color(orange)(p^0)/color(orange)(p^-1)#
#=color(purple)1/color(purple)2*color(red)(m^(-2-2))*color(green)(n^(-4-(-4)))*color(orange)(p^(0-(-1)))#
#=color(purple)1/color(purple)2*color(red)(m^(-4))*color(green)(n^(-4+4))*color(orange)(p^(0+1))#
#=color(purple)1/color(purple)2*color(red)(m^(-4))*color(green)(n^0)*color(orange)(p^1)#
#=color(purple)1/color(purple)2*color(red)(m^(-4))*color(green)1*color(orange)p#
#=color(purple)1/color(purple)2*color(red)(m^(-4))*color(orange)p#
#=color(orange)p/color(purple)2*color(red)(m^(-4))#
#=color(orange)p/color(purple)2*1/color(red)(m^4)#
#=color(orange)p/(color(purple)2color(red)(m^4))#
That's the simplified result. Hope this helped!