The ratio of the roots of the a1x2+b1x+c1=0 be equal to the ratio of roots of a2x2+b2x+c2=0 then a1a2=b1b2=c1c2
Let α,β be the common roots of the quadratic equations a1x2+b1x+c1=0 and a2x2+b2x+c2=0.
Then,
α+β=−b1a1, αβ=c1a1
And α+β=−b2a2, αβ=c2a2
Therefore,
−ba1=−b2a2 and c1a1=c2a2
⇒a1a2=b1b2 and a1a2=c1c2
⇒a1a2=b1b2=c1c2
Hence, this is the answer.