3x+y=13 2x-y=7 metoda podstawiania

3x+y=13 2x-y=7 y=13-3x 2x-13-3x=7 y=13-3x -x=-6 /*-1 y=13-3x x=6 y=13-3*6 x=6 y=-5 x=6

y= 13- 3x 2x - y = 7 2x-(13-3x) = 7 2x-13+3x=7 5x=20 |:5 x=4 y= 13-3x y= 13-3×4=13-12=1 x=4 y=1