If x, y and z are real numbers such that: x + y + z = 5 and xy + yz + zx = 3, what is the largest value that x can have ?

(In reply to

solution by Charlie)

Charlie,

I may VERY WELL need sleep (I'm kinda tired), but doesn't x=5 require imaginary numbers (when the problem says that x, y, and z are all real).

--- SK