Respostas

2013-09-17T20:23:01-03:00
X² + 3xy = 0
x-y=2
-------

y=x-2

---------
x² + 3x(x-2) = 0

x² + 3x²-6x = 0

4x² - 6x = 0

x (4x-6)=0

4x-6=0

4x=6

x1=3/2
x2=0

(3/2)² + 3(3/2y) = 0 ~~~> 9/4 + 9/2y = 0

9/2y = -9/4

y1 = -0,5

y2=x2-2

y2=0-2

y2=-2

y1 + y2 = -0,5 + (-2) = -2,5 = -5/2

Alternativa "A"