Respostas

2013-05-19T18:05:43-03:00

x.y = 12

x = y+1

 

(y+1)y = 12

y² + y - 12 = 0

 

(-b ±√(b²-4ac))/2a

(-1 ±√(1-4(-12)))/2

(-1 ±√49)/2

(-1 ± 7)/2

 

y' = (-1 + 7)/2 = 3

y" = (-1 - 7)/2 = -4

 

x.3 = 12

x = 12/3

x = 4

1 5 1