来自丁华福的问题
5x-y=3,0.2x+0.3y=-0.9
5x-y=3,0.2x+0.3y=-0.9


5x-y=3,0.2x+0.3y=-0.9
5x-y=3,0.2x+0.3y=-0.9
5x-y=3,
0.2x+0.3y=-0.9
y=5x-3
0.2x+0.3(5x-3)=-0.9
0.2x+1.5x-0.9=-0.9
1.7x=0
x=0
y=5*0-3=-3
x=0
y=-3