Question

2x+y=3
x-3y=5

решить систему

Answer 1

2x+y=3
x-3y=5 |*-2

 

2x+y=3

-2x+6y=-10

-------------

7y=-7

y=-1

 

2x-1=3

2x=4

x=2

 

 

 

Answer 2

y = 3 - 2x

x - 3(3 - 2x) = 5

x - 9 + 6x = 5

7x = 14

x = 2

y = 3 - 4 = -1

Ответ. (2, -1)