x + y =20 18x + 13y = 800 Rozwiaze mi ktos to zadanie?

x+y=20 x=20-y 18(20-y)+13y=800 360-18y+13y=800 360-5y=800 -5y=440 y=-88 x-88=20 x=108 x=108 y=-88

x + y =20 /*(-13) 18x + 13y = 800 -13x-13 y =-260 /*(-13) 18x + 13y = 800 ------------------------ 5x=540 x=108 y=20-108=-88 x=108 y=-88