Question

решите систему уравнений:
{ х+4у=9
{ 3х+7у=2

Answer 1

x + 4y = 9
x = 9 - 4y
3( 9 - 4y ) + 7y = 2
27 - 12y + 7y = 2
- 5y = - 25
y = 5
x = 9 - 20 = - 11
Ответ ( - 11 ; 5 )

Answer 2

{x=9-4y
{27-12y+7y=2
{x=-11
{y=5