计算:1、(1+a)(a-1)(a²+1)2、(x+y)(x-y)+(x-y)²-x(x-3y)

问题描述:

计算:1、(1+a)(a-1)(a²+1)2、(x+y)(x-y)+(x-y)²-x(x-3y)

1、(1+a)(a-1)(a²+1)
=(a²-1)(a²+1)
=a^4-1
2、(x+y)(x-y)+(x-y)²-x(x-3y)
=x²-y²+x²-2xy+y²-x²+3xy
=x²+xy-y²