Odpowiedź:
a)
- x + 3y = 7
x + 2y = 3
dodajemy równania
- x + x + 3y + 2y = 7 + 3
5y = 10
y = 10/5 = 2
x + 2y = 3
x + 2 * 2 = 3
x + 4 = 3
x = 3 - 4 = - 1
Odp: x = - 1 , y = 2
b)
x + 4y = 11 | * (- 2)
2x - 5y = 10
- 2x - 8y = - 22
2x - 5y = 10
dodajemy rownania
- 2x + 2x - 8y - 5y = - 22 + 10
- 13y = - 12
13y = 12
y = 12/13
x + 4y = 11
x + 4 * 12/13 = 11
x + 48/13 = 11
x + 3 9/13 = 11
x = 11 - 3 9/13 = 10 13/13 - 3 9/13 = 7 4/13
Odp: x = 7 4/13 , y = 12/13
