a:d= Duplicate rate of (a−b)(b−c)
LHS=(ad)3=sqrtad(dh3)3d3=√dh3dd3h9d3=√h3=hRHSa−bb−c=dh3−dh2dh2−dh=dh2(h−1)dh(h−1)=h
∴LHS=RHS
Proved