If the foci of the ellipse $\large \frac{x^2}{25}+\frac{y^2}{9}=1$ are $(4,0)$ and $(-4,0)$, then for real number $\lambda$, the foci of the ellipse $\large \frac{x^2}{25+ \lambda^2}+\frac{y^2}{9+\lambda^2}=1$ are:

Your answer seems reasonable.
Find out if you're right!