||'''Book'''|| Advanced Engineering Mathematics ||
 ||'''Author'''|| Erwin Kreyszig ||
 ||'''Edition'''|| 8th Edition ||

/* code_begins */

{{{
reset()
x = var('x')
y = function('y',x) # define y a function of x
DE = diff(y,x)-(y +4*x)*(y+4*x)
print 'DE:';show(DE)

u = function('u',x)
DE = DE.subs({y:u-4*x,diff(y,x):diff(u-4*x,x)}) # substituting y/x as u
soln = desolve(DE,u)
soln = soln.simplify_full()
print 'Solution:';show(soln)
}}}

/* code_ends */

 * '''Solution by''': 
   * <Your Name>, <Profession>, <Organization>
   * <Your Name>, <Profession>, <Organization>