It is given that
a, b, c are in continued proportion
\[\frac{p{{a}^{2}}+qab+r{{b}^{2}}}{p{{b}^{2}}+qbc+r{{c}^{2}}}=\frac{a}{c}\]
Consider a/b = b/c = k
So we get
a = bk and b = ck ….. (1)
From equation (1)
a = (ck) k = \[c{{k}^{2}}\] and b = ck
We know that
Therefore, LHS = RHS.