Question

{2x + 5y = 7
{x + 2y = 2. ​

Answer 1

метод подстановки:

$\displaystyle \left \{ {{2x+5y=7} \atop {x+2y=2}} \right. \\\\\left \{ {{2x+5y=7} \atop {x=2-2y}} \right. \\\\2(2-2y)+5y=7\\y=3\\x=2-2*3\\x=-4\\(x,y)=(-4,3)$

Answer 2

Ответ:

(x, y)=(–4, 3)

Объяснение:

{2x + 5y = 7

{2x + 5y = 7{x + 2y = 2

{2x+5y=7

{x=2-2y

2(2-2y)+5y=7

y=3

x=2-2*3

x= - 4

(x, y)=(–4, 3)

{2*(-4)+5*3=7

{-4+2*3=2

{7=7

{2=2

(x, y)=(–4, 3)