metodą podstawiania x+y=2 y-2x=3 y=2-x 2-x-2x=3 y=2-x -3x=1 |:-3 y=2-x x=-⅓ y=2-(-⅓) y=2⅓ x+y=4 y-2x=-2 y=4-x 4-x-2x=-2 y=4-x -3x=-6 |:-3 y=4-x x=2 y=4-2 y=2
1. Metoda podstawiania ( x + y = 2 ( y - 2x = 3 ( y = 2 - x ( 2 - x - 2x = 3 ( y = 2 - x ( - x - 2x = 3 - 2 ( y = 2 - x ( - 3x = 1 /:(-3) ( y = 2 - x ( x = -⅓ ( y = 2 + ⅓ ( x = -⅓ ( x = -⅓ ( y = 2⅓ Metoda przeciwnych współczynników ( x + y = 2 ( y - 2x = 3 ( x + y = 2 /*2 ( -2x + y = 3 ( 2x + 2y = 4 ( -2x + y = 3 ___________ 2x - 2x + 2y + y = 4 + 3 3y = 7 /: 3 y = 2⅓ x + y = 2 x = 2 - y x = 2 - 2⅓ x = -⅓ ( x = -⅓ ( y = 2⅓ 2. Metoda podstawiania ( x + y = 4 ( y - 2x = -2 ( y = 4 - x ( 4 - x - 2x = -2 ( y = 4 - x ( - x - 2x = -2 - 4 ( y = 4 - x ( - 3x = -6 /:(-3) ( y = 4 - x ( x = 2 ( y = 4 - 2 ( x = 2 ( x = 2 ( y = 2 Metoda przeciwnych współczynników ( x + y = 4 ( y - 2x = -2 ( x + y = 4 /*2 ( - 2x + y = -2 ( 2x + 2y = 8 ( - 2x + y = -2 ____________ 2x - 2x +2y + y = 8 - 2 3y = 6 /:3 y = 2 x + y = 4 x = 4 - y x = 4 - 2 x = 2 ( x = 2 ( y = 2