Moment distribution is based on the method of successive approximation developed by Hardy Cross (1885–1959) in his stay at the University of Illinois at Urbana-Champaign (UIUC). This method is applicable to all types of rigid frame analysis.
Summary for the value of end moments and deflection of perfectly restrained beam carrying various loadings. Note that for values of EIy, y is positive downward.
Case 1: Concentrated load anywhere on the span of fully restrained beam
End moments
$M_A = -\dfrac{Pab^2}{L^2}$
$M_B = -\dfrac{Pa^2b}{L^2}$
Value of EIy
$\text{Midspan } EI\,y = \dfrac{Pb^2}{48}(3L - 4b)$