x^6-10x³+16=(x³-8)(x³-2)=(x-2)(x²+4+2x)(x³-2)7x²-6x-11 -17 1(x-1)(7x+1)x²-3(a+1)x+3a+21 -3a-21 -1(x-3a-2)(x-1)(4)ax²-(1-a)x-11 1a -1(x+1)(ax-1)解方程并写出解集x²+1=02x²-3x-2=0-3x²+20x+7=0x²+1=0空集2x²-3x-2=01 -22 1(x-2)(2x+1)=0x=2x=-1/2-3x²+20x+7=0-173 1(-x+7)(3x+1)=0x=7x=-1/3