dnf魔道安图恩打法:想对对答案,几道分解的题

来源:百度文库 编辑:高考问答 时间:2024/04/29 12:23:47
注:'[2]'指的是前面的数或字母的平方,还有请务必写出过程

1. 4xy+1-4x[2]-y[2]
2. x[2]-9y[2]-2x+6y
3. 4a[2]+9b[2]-49c[2]-12ab
4. a[5]+2a[3]b[2]-24ab[4]
5. a[2]+4+b[2]-5a-2ab+5b

1.原式=-(4x[2]-4xy+y[2])+1
=-(2x-y)[2]+1
=1-(2x-y)[2]
=(1+2x-y)(1-2x+y)
2.原式=x[2]-2x+1-1-(9y[2]-6y+1)+1
=(x-1)[2]-(3y-1)[2]
=(x-1+3y-1)(x-1-3y+1)
=(x+3y-2)(x-3y)
3.原式=(4a[2]-12ab+9b[2])-49c[2]
=(2a-3b)[2]-49c[2]
=(2a-3b+7c)(2a-3b-7c)
4.原式=a(a[4]+2a[2]b[2]-24b[4])
=a(a[2]+6b[2])(a[2]-4b[2])
5.原式=a[2]-2ab+b[2]-5a+5b+4
=(a-b)[2]-5(a-b)+4
=(a-b-1)(a-b-4)