David wants to find the solutions of this system of equations:

–4x – 7 = y

x2 – 2x – 6 = y

Which statement is true?

There are no real number solutions.
There is one unique real number solution at (–1, –3).
There is one unique real number solution at (1, –3).
There are two real number solutions at (–1, –3) and (1, –7).