#f(x)=-4x^5+3x^2-5/x^2#
#d/(d x) f(x)=color(red)(d/(d x)( -4x^5))+color(blue)( d/(d x)(3x^2))-color(green)(d/(d x)(5/x^2))#
#color(red)(d/(d x)( -4x^5))=-20x^4#
#color(blue)(d/(d x)(3x^2))=6x#
#color(green)(d/(d x)(5/x^2))=(0*x^2-2x*5)/(x^2)^2=(-10x)/x^4#
#d/(d x) f(x)=-20x^4+6x-(10x)/x^4#
#d/(d x) f(x)=(-20x^(16)+6x^5-10x)/x^4#