Question

x+y=3
5x+y=15
me ajudem pvf​

Answer 1

resolução!

x + y = 3 * (-1)

5x + y = 15

_____________

- x - y = - 3

5x + y = 15

4x = 12

x = 12/4

x = 3

y = 3 - x

y = 3 - 3

y = 0

S = { x = 3 e y = 0 }

Answer 2

Resposta:

x+y=3  (i)

5x+y=15 (ii)

(I)-(ii)

-4x=-12

x=3

y=3-x=3-3=0