Problem: y'=f(at+by+c) where a,b, and c are constants. Show that the substitution of x=at+by+c changes the equation to the separable equation x'=a+bf(x). Use this method to find the general solution of the equation y'=(y+t)^2 I really have no clue on this one. If someone could start me off in the right direction that would be great. I'm not seeing how they get that separable eq.