Question

resolva o sistema x.y=5 x+y=6

Answer 1

{x.y=5
{x+y=6
x=6-y
(6-y).y=5
6y-y^2=5
-y^2+6y=5
-y^2+6y-5=0
delta=b^2-4ac
delta=6^2-4.(-1).(-5)
delta=36-20
delta=16
y=-b-/+ raiz de delta/2a
y=-6-4/2.(-1)
y=-10/-2
y=5
y=-6+4/2.(-1)
y=-2/-2
y=1
S={(5, 1)}