Question

rezolva sistemul de ecuatie:

Answer 1

Răspuns:

Din x+y=3 => x=3-y si inlocuim:

xy=-10 <=> y(3-y)=-10 <=> - y^2+3y+10=0 |*(-1)

y^2-3y-10=0

Delta= 9-4*(-10)=9+40=49 >0 =>

=> y1=(3+7)/2=10/2=5

y2=(3-7)/2=(-4)/2=-2

Daca y=5 => x=3-5=-2

Daca y=-2 => x=3+2=5