Question

1. Resolva o sistema:

a) x² + y² = 20
x + 2y = 8



PRECISO DISSO ATE HJ!

Answer 1

Resposta:

x²+y²= 20

x +y = 6 ------> x=6-y

(6-y)² + y² = 20

36 - 12y + y² +y²= 20

36 - 12y +2y² - 20 = 0

2y² - 12y + 16= 0

y² - 6y + 8 = 0

Δ = 36 - 32 = 4

√Δ = √4 = 2

y' = (6+2)/2= 4

y"= (6-2)/2= 2

x+y=6

para y = 4 ---> x= 6-4=2

para y = 2 ---> x= 6-2= 4