Any way to solve parametric inequations?

[Albert Chan]

CAS> assume(y≥0)
CAS> solve(x*y/(x+y)^2 ≤ 0, x)       → {x<(-y),(x>(-y)) AND (x≤0)}
CAS> assume(y<0)
CAS> solve(x*y/(x+y)^2 ≤ 0, x)       → {(x≥0) AND (x<(-y)),x>(-y)}

Or, for y≠0, reduce to simple inequality, with t = x/y

CAS> solve(t/(t+1)^2 ≤ 0, t)            → {t<-1,(t>-1) AND (t≤0)}