帮我检查一下有没有错,
来源:学生作业帮 编辑:搜搜做题作业网作业帮 分类:数学作业 时间:2024/06/28 10:53:27
帮我检查一下有没有错,
![](http://img.wesiedu.com/upload/a/c9/ac91d277886260e30e86fd859704a691.jpg)
![](http://img.wesiedu.com/upload/4/42/4422d12eb1d561165e252fdffedf82e9.jpg)
![](http://img.wesiedu.com/upload/f/65/f651ea1d1d2f68176ae605570f77e44e.jpg)
![](http://img.wesiedu.com/upload/5/83/58361204ced8ef437afed10ae779a00e.jpg)
![](http://img.wesiedu.com/upload/a/c9/ac91d277886260e30e86fd859704a691.jpg)
![](http://img.wesiedu.com/upload/4/42/4422d12eb1d561165e252fdffedf82e9.jpg)
![](http://img.wesiedu.com/upload/f/65/f651ea1d1d2f68176ae605570f77e44e.jpg)
![](http://img.wesiedu.com/upload/5/83/58361204ced8ef437afed10ae779a00e.jpg)
![帮我检查一下有没有错,](/uploads/image/z/5122741-13-1.jpg?t=%E5%B8%AE%E6%88%91%E6%A3%80%E6%9F%A5%E4%B8%80%E4%B8%8B%E6%9C%89%E6%B2%A1%E6%9C%89%E9%94%99%2C)
答案最后一个对了,其他的都错了
(1) =[(x+3)(x-3)]²
=(x²-9)²
=x的4次方-18x²+81
(2)=[(x+2y)-z]²
=(x+2y)²-2z(x+2y)+4z²
=x²+4xy+4y²-2xz-4yz+4z²
(3)=4x²-4y²-(4x²-4xy+y²)
=4x²-4y²-4x²+4xy-y²
=4xy-5y²
(1) =[(x+3)(x-3)]²
=(x²-9)²
=x的4次方-18x²+81
(2)=[(x+2y)-z]²
=(x+2y)²-2z(x+2y)+4z²
=x²+4xy+4y²-2xz-4yz+4z²
(3)=4x²-4y²-(4x²-4xy+y²)
=4x²-4y²-4x²+4xy-y²
=4xy-5y²