Question

Способ подстановки: x-3y =4; 2x-y=3

Answer 1

X-3y=4
2x-y=3,

x=3y+4
2x-y=3,

2(3y+4)-y=3
6y+8-y=3
5y=-5
y=-5:5
y=-1
X=3•1+4
X=7
Y=-1
Ответ:(7;-1)

Answer 2

{x-3y =4   
{2x-y=3

{x = 3y+4
{2(3y+4)-y=3

{x = 3y+4
{6y+8-y=3

{x = 3y+4
{5y=3-8

{x = 3y+4
{5y=-5

{x = 3y+4
{y=-1

{x = 3*(-1)+4
{y=-1

{x = 1
{y=-1

Ответ: (1; -1)