15. Determine the equation of the line

In an isosceles \(\triangle ABC\), \(AB = AC\). The base \(BC\) lies on the \(x\)-axis, \(A\) lies on the \(y\)-axis, and $x+9y+18=0$ is the equation of \(AB\). Find the equation of the straight line along with \(AC\).

 

Answer:

 

The equation of the straight line along \(AC\) is