(x-1)(y+1)=3 即xy+x-y=4 又xy(x-y)=4所以 xy=x-y=2 y^2+2y+1=3 y=-1+3^(1/2) y=-1-3^(1/2)x=1+3^(1/2) x=1-3^(1/2)x的7次方+y的7次方=(-1+3^(1/2))^7+(1+3^(1/2))^7=(-1-3^(1/2))^7+(1-3^(1/2))^2
