2x+y=9 |*4 5x-4y=3 8x+4y=36 5x-4y=3 --------- 13x=39 x=3 2*3+y=9 6+y=9 y=9-6 y=3 x-2y=3 -2x+y=0 |*2 x-2y=3 -4x+2y=0 ---------- -3x=3 x=-1 -1-2y=3 -2y=3+1 -2y=4 y=-2
2x+y=9 5x-4y=3 y=9-2x 5x-(4*(9-2x))=3 y=9-2x 5x-(36-8x)=3 y=9-2x 13x=39 |:3 y=9-2x x=3 y=9-2*3=9-6=3 x-2y=3 -2x+y=0 x=3+2y -2(3+2y)+y=0 x=3+2y -6-4y+y=0 x=3+2y -3y=6 |:-3 x=3+2y y=-2 x=3-4=-1
2x+y=9 5x-4y=3 y=9-2x 5x-4*(9-2x)=3 y=9-2x 5x-36+8x=3 y=9-2x 5x+8x=39 y=9-2x 13x=39 y=9-2x x=3 y=9-2*3 y=3 x=3 teraz drugie x-2y=3 -2x+y=0 x=3+2y -2*(3+2y)+y=0 x=3+2y -6-4y+y=0 x=3+2y -3y=6 y=-2 x=3+2*(-2) y=-2 x=-1
