2003/10/17 (金) 11:38:11        [mirai]
aX+bY=c
dX+eY=f
X=(c-bY)/a
d(c-bY)/a+eY=f
c-bY+ae/dY=fd/a
ae/d-bY=fd/a-c
Y=(fd/a-c)/(ae/d-b)