Help for this page
.75* (.75/x) * (.75/x) * (.75/x)
.5 * (.5/x) * (.5/x) * (.5/x) + .5 * (.25*2/x) * (.5/x) * (.5/x) ... + .25* (.25*x12) * (.5/x1) * (.25*x12) + .25* (.5/x1) * (.25*x12) * (.25*x12) + .25* (.25*x12) * (.25*x12) * (.25*x12)