Question 11
The value(s) of $y$ for which the following pair of equations $$
\begin{aligned} x^2+y^2-16&=0,\\ x^2-3y+12&=0 \end{aligned}
$$ may have a real common solution, are:
\begin{aligned} x^2+y^2-16&=0,\\ x^2-3y+12&=0 \end{aligned}
$$ may have a real common solution, are: