1.计算(a^2+a+1)(a^2-a+1) 2.计算(x-y)(x+y)+(3x-2y)(2x+y)-x(6x-y)

1。(a²+a+1)(a²-a+1) =[(a²+1)+a][(a²+1)-a]=(a²+1)²-a²=a^4+2a²+1-a²=a^4+a²+12。(x-y)(x+y)+(3x-2y)(2x+y)-x(6x-y)=x²-y²+6x²-xy-2y²-6x²+xy=x²-3y²