Question

exercitiul 4 , doar b si c . va rog ! dau coroana

Answer 1

Explicație pas cu pas:

(x+y)^2=(-4)^2

x^2+y^2+2xy=16

Dar x^2+y^2=40

40+2xy=16

2xy=16-40=-24

xy=-12

x+y=-4

x=-4-y

y(-(4+y)=-12

-y(4+y)=-12

-4y-y^2=-12

-(y^2+4y)=-12

y^2+4y=12

y^2+4y-12=0

(y+6)(y-2)=0

y+6=0

y=-6, x=-4-(-6)=-4+6=2

y-2=0

y=2, x=-4-2=-6