A tank has an intake valve and a release valve. The rate of follow through each valve is inversely proportional to the area of its cross-section. The cross-section area of the input can be described by the equation, f(x)= x^2+2x+1; The cross-section area of the release can be described by the equation, f(x)= x^2+4x+3. If the proportion constant is equal for the input and output, find x such that the volume of material in the tank remains constant.