Question

3 x + y = 15
x+ 5y = -15​

Answer 1

Respuesta:

x = 40/7

y = 15/7

Explicación paso a paso:

3 x + y = 15

x+ 5y = -15

Despejamos x:

x = (y - 15)/3 y x = -15 -5y

Igualamos:

(y - 15)/3 = -15 -5y

y - 15 = 3(-15 -5y)

y - 15 = -45 -15y

14y = -30

y = 30/14

y = 15/7

Reemplazamos "y":

3x + y = 15

3x + (15/7) = 15

(21x-15)/7 = 15

21x -15 = 7(15)

21x -15 = 105

21x = 120

x = 120/21

x = 40/7