Question

Find the number of real solutions of the system of equations.

x^2−y^2=z
y^2−z^2=x
z^2−x^2=y

Answer 1

i know already...

solutions are:

(1) x=-1; y=0; z=1
(2) x=0; y=0; z=0
(3) x=0; y=1; z=-1
(4) x=1; y=-1; z=0

so there are 4 real solutions...