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)
答
(1+a)(a-1)(a^2+1)
=(a^2-1)(a^2+1)
=a^4-1
(x+y)(x-y)+(x-y)^2-x(x-3y)
=(x^2-y^2)+x^2+y^2-2xy-x^2+3xy
=x^2+xy
答
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