#sqrt((5c^5)/(4d^5))#
#:.=(sqrt(5c^5))/(sqrt(4d^5))#
#:.=sqrt(5*c*c*c*c*c)/sqrt(2*2*d*d*d*d*d)#
#:.=(c^2sqrt(5c))/(2d^2sqrtd)#
#:.=(c^2sqrt(5c))/(2d^2sqrtd) xx (2d^2sqrtd)/(2d^2sqrtd #
#:.=(cancel2^color(blue)1c^2cancel(d^2)sqrt(5cd))/(cancel4^color(blue)2cancel(d^5)^3#
#:.color(blue)(=(c^2sqrt(5cd))/(2d^3)#