Question

Система x-y=3 -x-4y=7

Answer 1

X - y = 3 
- x - 4y = 7 
x - x - y - 4y = 3 + 7 
- 5y = 10 
y = - 2 
x + 2 = 3 
x = 1 
Ответ ( 1 ; - 2 )

Answer 2

-5y=10
y=-2
x=1. !!!!!!!