Question 977097
You could assume vertical symmetry axis and try using standard form.


{{{y=a(x-h)^2+k}}}

{{{7=a(0-h)^2+k}}}
{{{7=ah^2+k}}}


The other point:
{{{-2=a(-3-h)^2+k}}}


You still have only two equations but three unknown variables.  One more point needs to be known or given.