(1)a/3+x/3=0 与4a-4y-4=0同解 所以
x=y,又x=-a,y=a-1
=> -a=a-1 =>a=1/2
(2)x+y=-1
所以(x+y)+(x+y)平方+(x+y)立方+.+(x+y)2009次方= -1