Consider $3x^{2}+ax+14xy-5y^{2}+5ay$ as a polynomial over variable $a$.
$$\left(x+5y\right)a+14xy+3x^{2}-5y^{2}$$
Find one factor of the form $ka+m$, where $ka$ divides the monomial with the highest power $\left(x+5y\right)a$ and $m$ divides the constant factor $3x^{2}+14xy-5y^{2}$. One such factor is $x+5y$. Factor the polynomial by dividing it by this factor.
