3 X=5 y ① X- y=4.4 ② 由②得x=y+4.4 ③ 将③代入①得3(y+4.4)=5y 3y+13.2=5y 3y-5y=-13.2 -2y=-13.2 y=6.6 所以x=y+4.4=11 所以x=11,y=6.6
