整理的
x=5y+9代入 2x-5=y+3得2(5y+9)-5=y+3解得y=-10/9 x=31/9
解:{X+1=5(Y+2) (1)
{2X-5=Y+3 (2)
由(1)得,
X+1=5Y+10
X=5Y+9 (3)
把(3)代入(2),得,
2(5Y+9)=Y+3
10Y+18-5=Y+3
9Y=-10
Y=-9分之10 (4)
把(4)代入(3),得,
X=9分之31