方程(x-1)(x+2)=0的两根分别为( )
A:x1=-1,x2=2
B:x1=1,x2=2
C:x1=-1,x2=-2
D:x1=1,x2=-2
Does she want ____ (join) the club?
设z=1+i(i是虚数单位),则2z+z2等于( )