Question

Решите систему уравнений
3х + у = 1
(х + 1)/3 - у/5 = 2

Answer 1

3x + y = 1
(x + 1)/3 - y/5 = 2    /*15

3x + y = 1
5(x + 1) - 3y = 30

3x + y = 1
5x + 5 - 3y = 30

3x + y = 1     /*3
5x - 3y = 25

9x + 3y = 3
5x - 3y = 25
-------------------- + 
14x = 28
x = 2

y = 1 - 3x = 1 - 3*2 = 1 - 6 = - 5

Ответ
( 2 ; - 5)