(x+2y)(x-2y)*(x²-4y²)
问题描述:
(x+2y)(x-2y)*(x²-4y²)
答
计算:(x+2y)(x-2y)*(x²-4y²)=(x²-4y²)²=(x²)²-8x²y²+16(y²)² (工具不好)
应当是:(x+2y)(x-2y)*(x²+4y²)==(x²)²-16(y²)²