
(2)、x²-(5a+1)x+4a²+a=0x²-(5a+1)x+a(4a+1)=0(x-a)[x-(4a+1)]=0x=a或x=4a+1(3)、x²+2(a+1)x+(a²+2a+1)²=0x²+2(a+1)x+(a+1)²=0[x+(a+1)]²=0x=-(a+1)

(2)、x²-(5a+1)x+4a²+a=0x²-(5a+1)x+a(4a+1)=0(x-a)[x-(4a+1)]=0x=a或x=4a+1(3)、x²+2(a+1)x+(a²+2a+1)²=0x²+2(a+1)x+(a+1)²=0[x+(a+1)]²=0x=-(a+1)