x+y+yx = 5
(x+y)xy = 6
s+p = 5
s•p = 6
S = 5
P = 6
t²-St+P = 0 => t²-5t+6 = 0
Delta = 25-24 = 1 => t1,2 = (5±1)/2
=> t1 = 2, t2 = 3
=> s = 2, p = 3 sau s = 3, p = 2
=> x+y = 2
=> xy = 3
t²-2t+3 = 0
Delta = 4-12 < 0 (nu avem soluții)
x+y = 3
xy = 2
t²-3t+2 = 0
Delta = 9-8 = 1
=> t1,2 = (3±1)/2
=> a = 1, b = 2 sau a = 2, b = 1.
