6x-3y=9 x+5y=-9,5

6x-3y=9 x+5y=-9,5 /*(-6) 6x-3y=9 -6x-30y=57 -------------------dodajemy -33y=66 y=-2 x+5y=-9,5 x=-9,5-5y x=-9,5-5*(-2) x=-9,5+10 x=½

6x-3y=9/:3 x+5y=-9,5 2x-y=3 x+5y=-9,5/×(-2) 2x-y=3 -2x-10y=19 2x-y-2x-10y=3+19 -11y=22/:(-11) y=-2 2x-(-2)=3 2x+2=3 2x=1/:2 x=½