Question

Resolva o sistema:
x - y = 11
xy= -30

Answer 1

x=11+y

(11+y)*y=-30
y²+11y+30=0

y'=[-11+√(121-120)]/2=(-11+1]/2=-5

y''=[-11-√(121-120)]/2=(-11-1]/2=-6

Se y =-5  ==>x=11+y=6

Se y =-6  ==>x=11-6=5