dsolve(diff(y(x),x) = (a^3+y(x)^4*a^3+2*y(x)^2*a^2*b*x^2+a*x^4*b^2+y(x)^6*a^3+3*y(x)^4*a^2*b*x^2+3*y(x)^2*a*b^2*x^4+b^3*x^6)*x/a^(7/2)/y(x),y(x))