Odpowiedź:
3(x + 1) - (y - 2) = 9
2x+ y = 6
3x + 3 - y + 2 = 9
2x + y = 6
3x - y + 5 = 9
2x + y = 6
3x - y = 9 - 5
2x + y = 6
3x - y = 4
2x + y = 6 ⇒ y = - 2x + 6 wstawiamy do pierwszego równania
3x - (- 2x + 6) = 4
3x + 2x - 6 = 4
5x = 4 + 6
5x = 10
x = 10/5 = 2
y = - 2x + 6 = - 2 * 2 + 6 = - 4 + 6 = 2
sprawdzenie:
3(x + 1) - (y - 2) = 9
3(2 + 1) - (2 - 2) = 9
3 * 3 - 0 = 9
9 = 9
L = P
2 * 2 + 2 = 6
4 + 2 = 6
6 = 6
L = P
