1、(3a-2b)(-2b-3a)2、化简求值(3a-1)²-3(2-5a+3a²) a=三分之一3、(2x-y)(2x+y)(4x²-y²)4、已知a(a+1)-(a²+b)=-4,求(2分之a²+b²)-ab
来源:学生作业帮助网 编辑:作业帮 时间:2024/07/10 13:14:28
![1、(3a-2b)(-2b-3a)2、化简求值(3a-1)²-3(2-5a+3a²) a=三分之一3、(2x-y)(2x+y)(4x²-y²)4、已知a(a+1)-(a²+b)=-4,求(2分之a²+b²)-ab](/uploads/image/z/12541964-68-4.jpg?t=1%E3%80%81%283a-2b%29%28-2b-3a%292%E3%80%81%E5%8C%96%E7%AE%80%E6%B1%82%E5%80%BC%EF%BC%883a-1%29%26%23178%3B-3%EF%BC%882-5a%2B3a%26%23178%3B%EF%BC%89+a%3D%E4%B8%89%E5%88%86%E4%B9%8B%E4%B8%803%E3%80%81%EF%BC%882x-y%EF%BC%89%EF%BC%882x%2By%EF%BC%89%EF%BC%884x%26%23178%3B-y%26%23178%3B%EF%BC%894%E3%80%81%E5%B7%B2%E7%9F%A5a%EF%BC%88a%2B1%EF%BC%89-%EF%BC%88a%26%23178%3B%2Bb%29%3D-4%2C%E6%B1%82%EF%BC%882%E5%88%86%E4%B9%8Ba%26%23178%3B%2Bb%26%23178%3B%EF%BC%89-ab)
1、(3a-2b)(-2b-3a)2、化简求值(3a-1)²-3(2-5a+3a²) a=三分之一3、(2x-y)(2x+y)(4x²-y²)4、已知a(a+1)-(a²+b)=-4,求(2分之a²+b²)-ab
1、(3a-2b)(-2b-3a)
2、化简求值(3a-1)²-3(2-5a+3a²) a=三分之一
3、(2x-y)(2x+y)(4x²-y²)
4、已知a(a+1)-(a²+b)=-4,求(2分之a²+b²)-ab
1、(3a-2b)(-2b-3a)2、化简求值(3a-1)²-3(2-5a+3a²) a=三分之一3、(2x-y)(2x+y)(4x²-y²)4、已知a(a+1)-(a²+b)=-4,求(2分之a²+b²)-ab
1)、(3a-2b)(-2b-3a)=(-2b)²-(3a)²=4b²-3a²
2)(3a-1)²-3(2-5a+3a²)
=9a²-6a+1-6+10a-9a²
=4a-5
当a=1/3时,原式=-11/3
3)(2x-y)(2x+y)(4x²-y²)=(4x²-y²)(4x²-y²)=16x的4次方-8x²y²+Y的4次方
4)a(a+1)-(a²+b)=-4
a²+a-a²-b=-4
a-b=-4
(a²+b²)/2-ab=1/2(a-b)²=1/2*16=8
1、=-(3a-2b)(2b+3a)
=(2b-3a)(2b+3a)
=4b的平方减去9a的平方
后面都是平方差公式或其变形。
1、 (3a-2b)(-2b-3a)
=-6ab-9a²+4b²+6ab
=4b²-9a²
2、(3a-1)²-3(2-5a+3a²)
=9a²-6a+1-6+15a-9a²
=9a-5
=3-5
=-2
3、(2x-y)(2x+y)(4x²-y²)
=(4x²-y²)(4x²-y²)
=(4x²-y²)²