1.计算:(-3x²)(-2xy+3xy²-x+1)(写过程)2.若﹣x²y=2 则﹣xy(x的5次方y²-x³y+2x)的值为 A16 B0 C 8 D123(﹣2a)(¼a³-1)=4.a(b+c)-ab=
来源:学生作业帮助网 编辑:作业帮 时间:2024/06/23 12:19:33
![1.计算:(-3x²)(-2xy+3xy²-x+1)(写过程)2.若﹣x²y=2 则﹣xy(x的5次方y²-x³y+2x)的值为 A16 B0 C 8 D123(﹣2a)(¼a³-1)=4.a(b+c)-ab=](/uploads/image/z/2515800-48-0.jpg?t=1.%E8%AE%A1%E7%AE%97%EF%BC%9A%28%EF%BC%8D3x%26%23178%3B%29%28%EF%BC%8D2xy%2B3xy%26%23178%3B-x%2B1%29%EF%BC%88%E5%86%99%E8%BF%87%E7%A8%8B%EF%BC%892.%E8%8B%A5%EF%B9%A3x%26%23178%3By%3D2+%E5%88%99%EF%B9%A3xy%EF%BC%88x%E7%9A%845%E6%AC%A1%E6%96%B9y%26%23178%3B-x%26%23179%3By%2B2x%EF%BC%89%E7%9A%84%E5%80%BC%E4%B8%BA+A16+B0+C+8+D123%28%EF%B9%A32a%29%EF%BC%88%26%23188%3Ba%26%23179%3B-1%EF%BC%89%3D4.a%EF%BC%88b%2Bc%EF%BC%89-ab%3D)
1.计算:(-3x²)(-2xy+3xy²-x+1)(写过程)2.若﹣x²y=2 则﹣xy(x的5次方y²-x³y+2x)的值为 A16 B0 C 8 D123(﹣2a)(¼a³-1)=4.a(b+c)-ab=
1.计算:(-3x²)(-2xy+3xy²-x+1)(写过程)
2.若﹣x²y=2 则﹣xy(x的5次方y²-x³y+2x)的值为 A16 B0 C 8 D12
3(﹣2a)(¼a³-1)=
4.a(b+c)-ab=
1.计算:(-3x²)(-2xy+3xy²-x+1)(写过程)2.若﹣x²y=2 则﹣xy(x的5次方y²-x³y+2x)的值为 A16 B0 C 8 D123(﹣2a)(¼a³-1)=4.a(b+c)-ab=
1.计算:(-3x²)(-2xy+3xy²-x+1)(写过程)
(-3x²) (-2xy+3xy²-x+1)
=(-3x²)(-2xy)+(-3x²)×3xy²-(-3x²)×x+(-3x²)×1
=6x³y-9x³y²+3x³-3x²
2.若﹣x²y=2 则﹣xy(x的5次方y²-x³y+2x)的值为 A16 B0 C 8 D12
﹣x²y=2
∴x²y=-2
﹣xy(x的5次方y²-x³y+2x)
=-x²y(x的4次方y²-x²y+2)
=2(4+2+2)
=16
选A
3(﹣2a)(¼a³-1)
=-1/2a的4次方+2a
4.a(b+c)-ab
=ab+ac-ab
=ac