If a, b, c are in continued proportion, prove that: \[\frac{p{{a}^{2}}+qab+r{{b}^{2}}}{p{{b}^{2}}+qbc+r{{c}^{2}}}=\frac{a}{c}\]
If a, b, c are in continued proportion, prove that: \[\frac{p{{a}^{2}}+qab+r{{b}^{2}}}{p{{b}^{2}}+qbc+r{{c}^{2}}}=\frac{a}{c}\]

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.