Метод исключения переменных:
x + 5y = 7
2x - y = 2
-2x - 10y = -14
2x - y = 2
-11y = -12
y = 12/11
2x - 12/11 = 2
x = 17/11
(x,y) = (17/11 , 12/11)
17/11 + 5 • 12/11 = 7
2 • 17/11 - 12/11 = 2
7 = 7
2 = 2
Методом подставки:
x + 5y = 7
2x - y = 2
x = 7 - 5y
2x - y = 2
2(7 - 5y) - y = 2
y = 12/11
x = 7 - 5 • 12/11
x = 17/11
(x,y) = (17/11,12/11)
17/11 + 5 • 12/11 = 7
2 • 17/11 - 12/11 = 2
7 = 7
2 = 2
